Brooklyn-based photographer Henry Hargreaves is a master of still life photography. His Band Rider series—made in collaboration with Caitlin Levin uses a Flemish painting style, these photos portrait the food and drink that many famous artists demand in their shows.
The reason she requests it without the bun is probably because of carbs
And the reason for the Diana picture is that she feels a connection with her and Diana was her inspiration (I think she only requests one when she's in the UK though)