I think they just want people to recognize who's in the photo. I mean, it *is* iconic, and I don't think people would be confused by who the mysterious guy is in the ad with Christine.
"During this performance, please feel free to let your cell phones and pagers ring willy-nilly. However, do remember that there are heavily-armed knights on stage and you might well be dragged up and impaled."
(Pre-curtain announcement at the new Broadway musical Monty Python's Spamalot)