The previously unseen image shows the couple surrounded by their young family members on a sofa during a get-together at Balmoral.
Buckingham Palace said the Duchess of Cambridge captured the moment on her camera during an event in 2018 with seven of the Queen and Philip’s great-grandchildren at the royal residence.
The full line-up of royal children includes the Duke and Duchess of Cambridge’s children Prince George and Princess Charlotte either side of the Queen, who holds their brother Louis.
Peter Phillip’s daughters Savannah and Isla are close to their great-grandfather and at the other end of the sofa are Zara and Mike Tindall’s children Lena, held by her cousin Isla, and his daughter Mia.
In another previously unseen photo released on Wednesday, the duke’s love of polo is shown with his son, Prince Charles.
The black and white image shared on Charles and Camilla’s official Twitter account shows both men sitting on polo ponies with mallets and helmets in hand during a match.
It was posted alongside a more modern image of the duke alongside his son and the duchess in the moments after William and Kate’s Westminster Abbey wedding.
The Duke and Duchess of Cambridge also shared memories of Philip and the Queen, posting an image taken at Balmoral in 2015 on their official Twitter account, showing the couple with their children George and Charlotte.
The Duke of Edinburgh’s ceremonial funeral will be held on Saturday in line with coronavirus restrictions, with a limit on the number of people who can attend and the expectation of face masks and social distancing for guests.
Broadcasters have yet to confirm their plans for Philip’s funeral, but the BBC and ITV are likely to devote several hours to the event, including the ceremony at 3pm.