Borked Portrait Panel Pic

I couldn't see the difference at first either, until @Mikezumi mentioned what we should be looking for. I don't recall having this happen before, but I've had an issue with portraits every time I've adopted a stray cat or horse. After a couple of sim days, all household portraits will become the cat or the horse, and only the top one ever stays highlighted.

I just chalk stuff like that up to game weirdness. And in my case, trash my save... lol :D