Backgrounds are fucked, artifacts sometines (like swirls and clothes merging into skin), AI very rarely does ugly people, flawed skin, or unusual facial expression.
Even with that, some are hard to tell.
I went 5 for 5 but if I hadn't known that one picture was AI each time and had just seen these pictures through normal means on the web I seriously doubt I would have even considered they could be fake
Glad I'm capable to correctly guess most of them- out of like 10 I only got 1 wrong.
Some people really do got ai-generated face looks though ,like one of the pictures which was the real one legit had what looked like an eyeball glitch but it just turned out to he a weird face shape + camera angle hiding the rim of her eyeball...