US President Donald Trump was left scratching his head when asked if he recognised a statue of a horse at Buckingham Palace – not realising it was his gift to the Queen.
Britain's head of state took the president and First Lady Melania Trump around an exhibition of American artefacts, items reflecting Mr Trump's Scottish heritage and love of golf, and documents and photos relating to royal visits to the US.
But when they came across a thoroughbred in polished pewter, the US leader did not know the artwork was his gift to the Queen when they met in July last year – yet Mrs Trump did.
The Queen led the Trumps around the exhibition in the palace's picture gallery after hosting a private lunch for them attended by the Prince of Wales, Duchess of Cornwall, Duke of Sussex, Duke of York and members of the Queen's household and president's entourage.
Tim Knox, director of the Royal Collection who joined the Queen during the tour, said Mr Trump gave the monarch the horse when he had tea with her at Windsor Castle.
He added that when Mr Trump was asked if he recognised it, he said "no" but "the First Lady did recognise it, which is rather nice".
Mr Knox joked: "But one horse looks very much like another."
The president is a well-known golf fan and he and the Queen pored over pictures of her father King George VI and uncle King Edward VIII playing golf at St Andrews in Scotland in the 1920s.
Nearby was a piece of MacLeod tartan – the family of the president's mother – and Mr Trump quickly spotted the yellow material which, like all the items, was from the Royal Collection.
Mr Knox said: "He immediately recognised it and said, 'That's my tweed'."
Charles, Camilla and Harry also entered the picture gallery, staying at the far end of the room, but Andrew joined the president's daughter Ivanka Trump, a former model, businesswoman and now a White House adviser, and her property developer husband Jared Kushner, who also works in the Oval Office, as they looked at the exhibits.
The Queen appeared to take a real interest in guiding her guests through the displays, which also featured pictures and documents chronicling the visit of her parents to America in 1939 and papers relating to George Washington.
Mr Knox added: "Really it's her collection, so it's really important she guides them through it, I'm there just in case I can help."
The Queen's official gifts to Mr Trump were a first edition of The Second World War by Winston S Churchill from 1959.
The crimson book features gold tooled decoration on the cover, spine and inner cover, an EIIR cypher in gold on the front, silk endpapers and hand-sewn headbands in the colours of the US flag with all pages edged in gilt.
The monarch also gave Mr Trump a three-piece Duofold pen set – a fountain pen, rollerball pen and ballpoint pen with EIIR cypher – using the obsidian design, exclusively made for the Queen.
Mrs Trump was presented with a specially commissioned silver box with a handcrafted enamel lid.