Across the room, over the canapes, I spot a fascinating creature. There, in the wild (aka a function in central London attended by a bunch of diplomats), is one of the authors of the Russian embassy in Britain's Twitter account. Politely shy and low-voiced, behind thick-rimmed glasses, Konstantin answers a few questions about the account, of which he's clearly proud. But when I ask for a full interview, he clams up.
"The message is newsworthy, not the vehicle," he says. I couldn't disagree more.
@RussianEmbassy is often one of Russia's liveliest, funniest and most outrageous Twitter accounts. To some it's a breath of fresh air in the over-formal, hyper-nuanced world of diplomacy. To others it's troll food, a rallying point for groups trying to drive a wedge between the West's citizens and their governments and institutions, following the Kremlin's dictat of divide and conquer.
Either way, it's a pioneer in the new world of Twitter diplomacy.
By their frogs shall ye know them. In January @RussianEmbassy tweeted out a complaint: "In today's papers pundits call on [British Prime Minister] Theresa May to disrupt possible Russia-US thaw. No trust in Britain's best friend and ally?”
Accompanying the tweet was a picture of Pepe the Frog, the green cartoon creature adopted
as the mascot of the alt-right, the far-right provocateurs who back Trump as their anti-establishment, anti-liberal champion.
It was a deliberate move. As Konstantin said (before he thought better of discussing his work with a reporter) "we are not afraid to be aggressive to get heard. If we use an image of Pepe the Frog and that means we get heard – then fine".
And as with any good sales pitch, there's a follow-up. Pinned to the top of the embassy's Twitter page is a link to the "Russian diplomatic online club", which promises "insights from top diplomats" – but which reportedly also recruits its members into Russia's ubiquitous Twitter bot army, automatically retweeting the ambassador's messages.
Welcome to the age of digital diplomacy. The era of high-level exchanges in cigar smoke-wreathed rooms is not entirely over, but a window has been thrown open to the world, and the ambassadors are peeking outside.
The first ambassador to tweet personally in his official capacity was Arturo Sarukhan, Mexico's ambassador to Washington, in 2009.
But the guru of ambassadorial Twittering is Tom Fletcher, the 42-year-old, Oxford-educated former foreign policy adviser at 10 Downing Street to Tony Blair, Gordon Brown and David Cameron, and who was the British ambassador to Lebanon from 2011 to 2015.
Fletcher sees social media as a new technology that is revolutionising diplomacy just as much as the telephone, the fax, or email did. And diplomacy must adapt or die (quite literally – he believes one day we may see the first war triggered by a tweet).
Fletcher says of the Russian Embassy in Britain: "They're much more fun than I am. I feel like they're the rookie drivers out now, and there's a few of us old guys, old-timers wandering about on Twitter being increasingly outraced.
"I am quite an admirer of what they do but I think they took it too far. The risk was they were doing it to get attention and retweets, but it lost some of its strategic purpose."
When he's asked to speak on digital diplomacy – or when he's asked for advice privately by ambassadors – Fletcher repeats his three rules: be "authentic, engaging and purposeful".
But he wonders if the Russians in Britain, and especially US President Donald Trump, have proven that his rules "no longer cut it".
"Those accounts are authentic, engaging and purposeful – yet they don't quite work," he says. He wonders if he needs a new rule – that a tweet must also be strategic, grounded to something solid beyond the ability to capture attention and project an attitude.
"I say to the ambassadors who are nervously approaching social media that we should not do a striptease on the Metro and put it up online. A lot of people will be laughing at you, not with you.
"We are not comedians or actors or social media ninjas. We are there to make a big impression, and it has to have an underlying purpose to it."
A good ambassador's Twitter feed should have a narrative and themes, he says. "Now and again you go off and talk about West Ham's match or Muhammad Ali, but there is at least a narrative running through it."
He'd love to know what the Russians are up to with their account; how much of it is policy.
"There is something quite deliberately disruptive," he says. "You can have benign and malign disruption, and in a way that tracks a lot of Russian foreign policy. [Russian President Vladimir] Putin's approach to the world is basically disruptive, that the current world order is not working and it's there to be chiselled away at and undermined."
As for Trump's Twitter diplomacy, Fletcher isn't a fan.
"The key to social media is also the key to politics, we're all craving authenticity," Fletcher says. "It's quite difficult to convey that authenticity on social media. I can't think of many leaders who've achieved that, and it's authentic Trump, it's him and that's the wonderful thing about it. It's why we all read it and talk about it.
"But I think it's maybe too soon to tell whether it's helping American diplomacy overall and helping Trump's reputation in the world. I would argue it's not; it's exposing real absence of leadership in the White House and exposing his own moral and psychological frailties.
"I've worked quite closely with lots of leaders … just about every leader is flawed in lots of interesting ways, and we've always seen it as our job as officials to conceal those flaws.
"North Korea is a classic example. The person in the street is much less likely to trust Trump [to deal with North Korea] because of his social media, which exposes his thought processes in such an ugly way.”
Fletcher says he was talked onto Twitter by his communications team in Lebanon, and he was the first ambassador in Beirut to take it up.
"We were building the plane as we flew it," he says. "To suddenly have an 'excellency' replying to tweets was a novelty – for better or worse."
Within weeks he was hooked, and developed a big local following. "Someone asked the director of comms at the Foreign Office, 'Aren't you worried about people like Tom Fletcher being out there expressing their opinions?' And he said, 'Well he's kind of showing us where the line's going to be'."
The challenge came when his tweets drew attention back in London, especially from British media. "Politicians do not like ambassadors taking up any domestic oxygen. But I would argue that horse has already bolted. If we want our people to be influential, social media doesn't stop at the English Channel."
He stepped over the line at least twice, he says, leading to him deleting tweets. Once he tweeted a photo of himself on a yacht, enjoying the ambassadorial lifestyle (and also referencing British yacht sales to Lebanon). He says these days he would argue it was a legitimate, if cheeky, tweet – but in those days both he and his bosses were nervous.
But the second he still regrets: he tweeted in support of a civil servants strike in Britain. It earned him a personal text from David Cameron, telling him to shut up.
"Everyone makes mistakes on social media, but the biggest mistake is not to be on it."
He also had some notable successes – his farewell letter to Lebanon went viral, and made him a celebrity in every Lebanese restaurant in the world. And a comment on Muhammad Ali's death also caught worldwide attention.
Australia is far from a digital diplomacy leader. The closest thing to an official leaderboard, at digital.diplomacy.live, ranks Britain, France and the US as the best, while Australia sits down at No.34, just above South Korea but below Thailand, Denmark and Bahrain.
Australia's outgoing high commissioner in Britain, Alexander Downer, has made some impact recently. On Twitter he claimed tennis player Johanna Konta as an Australian, which the British did not enjoy at all.
Downer has started to dip his toe in the water of social media, not least because it's official Department of Foreign Affairs and Trade strategy. "I just try to abide by the requirements of the department really, inspired more by them than by myself," he says, drily.
During his time at London's High Commission it has moved into Twitter and Facebook. "I don't know how good we are; we do our best," he says. "It's probably quite useful I think; it has a bit of a following."
If you're detecting a note of reservation, you're not wrong. Downer, thanks to his background, is comfortable in old-school media and regularly pops up on British television and radio. He's not impressed with Twitter as an opportunity to interact with the public. The feedback tends to include "gratuitous insults based on my former career – that I'm a war criminal, things like that".
Back in 2015 he was similarly reserved, telling a seminar that when he looked over the Twitter feeds of other embassies and foreign and Commonwealth office sites "there's very little there that is of the slightest interest to me".
"The problem is that the diplomatic messages are so bland, because the diplomats and the government officials are so fearful of getting into controversy and engaging in debate," he said then. "So when I look at those kinds of feeds I find them incredibly uninteresting. They're likely to be ineffectual, so the amount of effort you're putting into them is just ticking boxes.
"Follow the UN secretary-general's tweets. They are completely safe, as you'd expect. 'Met with foreign minister of Ruritania today. Met with secretary general of OAU today'. And that's it. After a while you're thinking 'That's one thing I can do to save time, not look at these any more'.
"He's obviously not doing these himself. It's not a criticism of him personally. But he could use his account to say something about what happened at the meeting … he should be using it for something like that."
Two years later, Downer thinks a good modern embassy is active on social media, and should do more than just post pictures of the ambassador opening art exhibitions. "It's not so much the feedback that interests me, it's feeding out our messages," he says.
And he suspects that the value of social media lies more as a channel to reach the media, rather than to reach "Mum and Dad" in the community.
"We could do more in all honesty to get across the Australian government's messages but you know, how much impact that would have I'm not sure. I think with digital diplomacy it's not just a record of your activities – fine as that is – but getting across messages about what Australia's doing and what it wants to do."
He says diplomacy involves a fine balance in order not to cut across the work of the government and ministers – his job is not to get into Australian media.
On the Russians, he wonders to what end they're doing it. "Yes they insult the British government and they mock them … humour always works here, but I'm not sure that it does anything really. It just makes Russia look like hostile territory."
Among his counterparts, he thinks Joe Hockey in the American embassy is using Twitter well, and the ambassador in Jakarta.
He also picks out Dave Sharma, who finished his most recent post as Australia's ambassador to Israel in June this year. Sharma is considered a bit of a pioneer of digital diplomacy in DFAT.
In a blog post a year ago Sharma – clearly a Fletcher fan – wrote he was a "big believer in the promise of social media for diplomats – I think it's essential if diplomacy is to reinvent itself and remain relevant in the modern age".
"Diplomacy is about the exertion of influence at the end of the day, and social media tools used widely enable diplomats to wield greater influence," he added.
However, evangelists "tend to gloss over the possibility that a digital diplomacy effort might all end horribly, in a veritable train wreck" Sharma said. "When you are out there, always seeking the edge, at times you will inevitably find yourself dangling perilously over it."
Risks involved inadvertently "creating daylight" between the messages from the embassy and Canberra, giving a negative story a new lease of life, or "engaging with critics and trolls in a way that quickly becomes unedifying and undignified".
"A digital mistake has an almost omnipresent quality," he said. "It can live and scar your life forever."
Not all ambassadors should be on Twitter, because it's better not to do it at all than to do it badly, Fletcher says.
But this is a "recruitment problem", because ideally every ambassador would be comfortable with it.
"If someone thinks their role is to hide away behind platitudes and protocol, then diplomacy is a dead profession. Unless it adapts to an age where there is a need to build public trust in what you're doing, then you suddenly realise the pews are empty and no one is listening to you."
In his book The Naked Diplomat, Fletcher writes on the same theme.
"For the first time, we have the means to influence the countries we work in on a massive scale, not just through elites.
"This is exciting, challenging and subversive. Getting it wrong could start a war … getting it right has the potential to rewrite the diplomatic rule book."
I raise this line with him. Is it really possible that one day a tweet could start a war? It is, he says. What if, for example, a Middle East embassy accidentally or unthinkingly hit the retweet button on an anti-Islam video or cartoon?
"Who knows how that could escalate," he says. "That's the kind of scenario I was thinking of."
Photo credit: Glenn Hunt