The Queen has wowed the leaders at the G7 summit, joking at a photocall: "Are you supposed to be looking as if you're enjoying yourself?"
The Queen's quip came as presidents and prime ministers smiled for the camera during a "family photo" after an evening reception at the Eden Project in Cornwall.
The 95-year-old monarch was joined by the Prince of Wales, the Duchess of Cornwall and the Duke and Duchess of Cambridge, in what was seen as a major royal charm offensive, and a huge boost for Prime Minister Boris Johnson as he aims to promote "Global Britain" on the world stage.
The leaders, from German Chancellor Angela Merkel to Canada's Prime Minister Justin Trudeau and US President Joe Biden, many with spouses, were pictured chatting to the royals.
After the 40-minute reception, they moved to an area to take a socially-distanced group photo, and after taking their seats, the Queen said: "Are you supposed to be looking as if you're enjoying yourself?"
The leaders around the Queen laughed as Mr Johnson said "yes", adding, "We have been enjoying ourselves - in spite of appearances."
Mrs Merkel walked over to the Queen and thanked her for posing for the picture, saying: "Thank you for doing that for us."
The royals also took time to carry out other engagements, including a meeting described by the Prince of Wales as "potentially game-changing" in which chief executives and the G7 leaders met to discuss how they could work together to tackle the climate crisis.
Speaking at the event, Prince Charles called on the G7 leaders to display the same sense of urgency in tackling climate change as they showed in tackling the coronavirus pandemic.
He said the battle against the pandemic provided a "crystal-clear example of the scale, and sheer speed, at which the global community can tackle crises when we combine political will with business ingenuity and public mobilisation".
He added: "We are doing it for the pandemic. So if you don't mind me saying so, we must also do it for the planet."
Using a slogan commonly used by Mr Johnson, he stressed: "To 'build back better' we need, above all, a truly effective partnership between government and business in order to mobilise finance and innovation, and to deliver a just transition for developed and developing economies alike."
Meanwhile the Queen, Camilla, and the Duchess of Cambridge attended an engagement to thank volunteers for their work during the pandemic.
The Queen, on sparkling form, insisted on borrowing a ceremonial sword to cut a cake during the event, prompting laughter from Camilla and Kate.
The monarch had been handed the sword by Edward Bolitho, the Lord-Lieutenant of Cornwall, for the task of cutting a large cake marking the Big Lunch at the Eden Project.
When told by an aide that there was a conventional knife available, the Queen replied: "I know there is. This is more unusual".
The Duchess of Cornwall commented: "That's slicing through," before assisting with the final part of cutting the cake, which was loudly applauded by those at the event.
After handing the ceremonial sword back, the Queen used a knife to cut a second slice of cake and remarked: "That looks very good."
The Queen's trip to Cornwall marked the start of a busy weekend for the 95-year-old.
On Saturday she will watch her official birthday parade at Windsor Castle and on Sunday she will host President Biden and the First Lady for tea.