Jimmy is right; James does pull the shorn head look off better than Daniel Radcliffe thanks to his tan... As for why James has a shaved head, it's for a new film by the name of Split, which is top secret (it's being directed by M. Night Shyamalan).
Then, just to show what a good dad he is, he let's Jimmy stroke his head, before inviting him to straddle his shoulders to bring him on a little ride around the studio. Given Jimmy's tendency towards accidents, James is a brave man - hence why he gets him to make a very brisk dismount.
