Apparently, this is a thing. I read about it on somebody's blog today, and started Googling. There are several companies that will set you up in London (or other destinations) with a photographer who will take photos of you (and your companion or companions) in various well-known spots (such as Houses of Parliament or London Bridge). This sounds good for someone like myself who travels solo. The only time I had photos of myself taken last year in England was when I ran into some fellow Whovians at the Earl's Court TARDIS, at the V&A (asked a randon stranger; turned out awful) and in Cotswolds (on Becky's Secret Cottage Tour; the guides are really nice and take good shots).
What do you think? The average price seems to be about $185 for a half-hour and 15 photos.