The poignant photograph of the late Queen mourning her husband of 73 years alone was widely shared at the time, and again following her death in September 2022.
Ahead of King Charles's coronation on 6 May, Princess Anne, 72, gave a rare interview to Canadian public broadcaster CBC in which she discussed her father's funeral. Asked if she felt her mother sitting alone was a "thievery", she replied: "Yes, you're quite right".
"In some ways I'm glad we didn't see that, at that moment," she explained. "When you see the photograph it's much worse somehow."
The coronavirus rules in place at the time limited funerals to 30 people, and Queen Elizabeth sat socially distanced from her family. Everyone in attendance wore face masks.
The powerful images of the Queen alone were widely recirculated again after it emerged that several gatherings had been held at 10 Downing Street during the coronavirus lockdown - with one of the events taking place on the eve of Prince Philip's funeral.
During the CBC interview, Princess Anne discussed how the coronavirus regulations had affected her father.
"COVID stole from my father, who lost a lot of the people who would have gone to see him and come and talk to him and have those conversations that would have kept him interested. He lost all of that," she said.
"I'm sure that there are lots of families who will tell you the same thing. For the older generation, losing those contacts - online didn't do that for everybody."
Anne rarely gives interviews, but recently topped the list of the hardest working royals - attending 214 engagements in 2022, far more than other members of her family, according to a tally from Reboot SEO Company.
Asked about the relevance of the royal family ahead of King Charles's coronation, and amid fears the day will be marred by protests, Princess Anne said the monarch provided a focus on service and goodness.
"It's perfectly true that there is a moment when you need to have that discussion [about the relevance of the monarch] but I would just underline that the monarchy provides, with the constitution, a degree of long-term stability that is actually quite hard to come by in any other way," she said.
'I rather hope that sometimes what we can do is just to underline the goodness and the fact that there are an awful lot of people out there who really do understand about the way they behave towards each other is important and that the monarchy provides an element of a focus to that level of service and encourages that in the long term.
'It's not a short-term thing. You're there for the long term.'