In terms of so-called fly-on-the-wall documentaries, there's a claim that the camera is a transparent window into a pre-existing reality. What really is happening is that the film crew and the subjects are collaborating to simulate a reality in which they pretend the camera is not present.

Once you recognize that all documentaries are performance, it's not a matter of 'if' they should be performance. They are performance, and they are performance precisely where people are playing themselves.

No one forgets the presence of the camera, no matter how long it's there.

Joshua Oppenheimer Quotes