You don't normally see big celebrities in fan t-shirts. They usually wear brands that sell things like $500 t-shirts, which is a concept I don't understand. I once saw Gucci sell a $2,000 t-shirt, but that at least had diamonds sewn into it. I'd just take the diamonds out, sell them, and then I'd still have a shirt. Genius.
It's especially fun seeing a celebrity who is an icon themselves wearing an iconic t-shirt. Arnold Schwarzenegger attempts to put an old Star Wars debate to rest by wearing his "Han Shot First" shirt. If you don't know what that means, then that means you probably had friends in high school. It doesn't look like Harrison Ford is mad at that. He's got a very rare smile on his face. I wonder if he's reminiscing about his plane crash.