I don't get it.
For context in this scene the Xenomorph Queen shows up and the Predator is supposed to look shocked.
This is how they try to make the Predator look shocked.
Well, not to be obnoxious, but I think it does look surprised. I mean, his eyes are wide open, so is his mouth. Not sure what else they could've done to make his face different, it's not like his mouth can open in diferent ways.
I am one of those rare individuals that actually thinks that AvP is quite good. I enjoyed that movie very much.