Buckingham Palace shared a historic portrait of the King and Queen with the Prince of Wales and the Duke of Edinburgh during Royal Week in Scotland.
It showed the foursome in their finery following the Thistle Service at St Giles' Cathedral in Edinburgh.
Charles, 75, Camilla, 76, Prince William, 42, and Prince Edward, 60, were pictured wearing the green Mantle of the Order of the Thistle velvet robes, white-plumed hats, and glistening insignia including the Thistle Stars for the ceremony.
While many royal watchers agreed it was a "beautiful" photograph, for others, the portrait provoked questions.
Some of the royal family's social media followers asked why the Duchess of Edinburgh was not wearing robes or included in the picture, despite attending the service.
The reason for this is that Sophie is not a Lady of the Thistle – the highest honour in Scotland. She may one day be given the honour as they are a personal gift of the King.
Prince Edward was appointed to the Order on his 60th birthday in March, while Queen Camilla was given the honour in June 2023
The order has a complement of 16 knights and ladies, and in addition the Queen, the Princess Royal and the Duke of Rothesay, as the Prince of Wales is known in Scotland, are Royal Knights of the Thistle.
Princess Anne did not travel up to Scotland from the service, as she is still recovering from concussion following her recent accident.
The Princess of Wales was also absent amid her ongoing cancer treatment.
Why Queen Camilla and Prince Edward have been given special honour
Those made Thistle Knights or Ladies have been recognised for holding public office or contributing significantly to national life.
The Queen was appointed chancellor of the University of Aberdeen in 2013 and in a speech to mark the 10th anniversary of her role at the institution, she said: "Coming to this university, and to this city, has always felt a bit like coming home to me.
"Firstly because my father's family came from this part of Scotland, secondly because my husband and I are lucky enough to spend precious time each year in Aberdeenshire, and finally because 10 years ago, I received the great honour of being installed as chancellor of this very special university."
Camilla is patron of Maggie's Cancer Care Centres, founded in Edinburgh in 1996 and now with sites across Scotland, England and Wales.
She is also patron or president of a number of charities based in Scotland, including Crathie Opportunity Holidays, Scotland’s Gardens Scheme and Horseback UK, and is an honorary member of the local Ballater Women’s Institute and the Upper Deeside Art Society.
Edward also holds several patronages of Scottish charitable organisations including the Edinburgh International Festival.