It actually does just look like palsy. Commenters claim his brow doesn't move but in the first response it does when he attempts to old man laugh. Think that's why half his forehead is smooth most of the time. That's the same half with the busted eye. If they were claiming his forehead didn't then that would be due to the botox but they specifically said brow. It's a pretty stiff minimal movement tho so I can see why they'd lean that way. Kind of think this pic is just something related to his ear piece since we've seen him lacking an ear hole once before at a debate.