The "Celebrity Photobomb" is one of the goofier segments on Jimmy Fallon's Tonight Show, but there's something inexplicably fun about watching ordinary tourists obliviously having their photos taken while Fallon and his guest companion play around behind them. The celebrity on Wednesday night's segment was Cameron Diaz, and she and Fallon managed to include a sub sandwich and Pharrell Williams' Mountie-inspired hats in their hijinks.
There seems to be a natural limit to how many times they can pull this prank, though: It's enough of a stretch to believe tourists in New York City would believe somebody wants to take their photo without asking for payment; how soon will it stop being believable that visitors at the top of NBC headquarters have never seen Fallon's Celebrity Photobombs? --Peter Weber