The touching snap, which is displayed on a decorative wooden table, shows the Queen alongside her three heirs, Prince Charles, Prince William, and Prince George, in a throwback photo from Christmas 2019.
WATCH: Prince Charles and Duchess Camilla arrive at the Oval for Jubilee Big Lunch
The video was shared by the Royal Commonwealth Society to remind applicants the deadline is fast approaching. This year's theme is "Our Commonwealth."
Camilla has a very close relationship with her mother-in-law and during the Platinum Jubilee Celebrations at the weekend, the Queen paid a touching tribute to the mother-of -two.
The frame behind Camilla shows the heartwarming photo
Her Majesty changed the social media account's header picture to one taken from her final appearance on the balcony of Buckingham Palace alongside Camilla and the other members of the royal family.
The image shows Her Majesty, standing front and centre alongside her heirs; Prince Charles, Prince William and great-grandchild Prince George, as well as the future consorts the Duchess of Cornwall and the Duchess of Cambridge.
Camilla enjoyed a packed jubilee weekend and even managed to squeeze in a secret party, which she and Prince Charles held on behalf of Her Majesty just hours before the epic Party at the Palace.
The royal family appeared out in force on the balcony of Buckingham Palace
Other royal attendees included the Duke and Duchess of Gloucester, the Duke of Kent, and Prince and Princess Michael of Kent. Noticeably missing were Prince William and Kate as well as Prince Harry and Meghan Markle.
The Duke and Duchess of Cambridge then watched the spectacular acts which headlined the epic concert including the likes of Queen and Adam Lambert, Alicia Keys, Craig David, Mabel, Elbow and George Ezra, Duran Duran and Andrea Bocelli.
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