Tom Cruise declined. Mariah Carey demurred. But it was easier with Mark Zuckerberg. And with Barack Obama. They agreed. As did Clint Eastwood and Ang Lee. And Angela Merkel. And Bill Clinton. George Clooney was up for anything. Rip into an old photo and affix the nose and eyes to his face with a rubber band, like a mask. Press the shutter. Presto. Pure irony. The shot that was seen around the world.