David Beckham is not quite on the Cristiano Ronaldo level of taking his shirt off on camera, but he certainly doesn't have an aversion to it. He also likes to do nice things for people and knows a lot of famous people. So of course he did the ALS Ice Bucket Challenge.
And of course he challenged Magic Johnson, Michael Jordan and Leonardo DiCaprio.
This is David Beckham. He doesn't wear shirts and he casually name drops famous people. This is his life.