When a performance isn't working, it's usually because the actor is trying to do something and they're not able to express their idea very well. It's a muddled expression.
Casey AffleckWhen you're the guy behind the camera, you're aware of the reasons for the compromises or the changes that get made. As an actor, you go and do your thing, and someone else down the line then does all the math and goes, "We can't include that thing where he's pretending to be dumb and needling those people, because it takes a minute and a half, and it ruins the next scene. It doesn't make sense." If you're directing, you're the one doing that.
Casey Affleck