Aha! This makes lots of sense to me.

Whenever I'm watching a movie with good actors, even though I know they are acting it's easy to let myself go and be absorbed by the story. They make it seem so easy (as most top professionals do) that sometimes I even start to think "acting can't be that hard!, I mean, you just have to reeeeally believe you are the character".

However in a low-budget movie, which usually has less skilled actors, you can definitely see this "System2-trying-to-fake-System1" behavior. This is also quite probably what would happen if someone filmed me trying to act, but I never found an explanation for why this happened.

Thanks for the recommendation, I'll definitely give it a go. It does look like a very interesting insight into human behavior.