A lesson for us all: photography isn't all about the camera or the lens or the film--great photos show a deeply ingrained and finely tuned sense of irony too. This is one of the funniest things I've seen in months. Well done!
I read it as a "movie shoot". The guy on the right is the director/DP, shooting with a cellphone, the guy in the middle is the actor and the woman on the left is the PA, taking notes. Probably students from an art college...?
Thanks for your comments. I remember I was in the middle of a busy road trying to take a photograph and avoid cars at the same time. Not to be recommended. This is one of my favourite corners in Edinburgh. It's always busy and there is always something going on. These days there's a lot of shooting going on with cellphones in the city.