I mean, I often jump into the animal cruelty argument but here... meh the cat seems fine perhaps not particularly amused by it. But look, if you put him in the box, take a pic, have a laugh for like 5 minutes and take him out I don't think it's even remotely animal cruelty. This is a cat they put themselves in even tighter spots so he ain't getting hurt, and I wouldn't be surprised if he actually enjoys it, cats like feeling cramped.