A filmed person can't act natural, They can't act like themselves.
Do We Have This One?? Up for Grabs
A documentary crew follows a character around because they're making a film and are trying to capture the couple's real life. The film crew asks the two to "Just act natural" and immediately Bob and Alice don't know how to do so. While under the camera's eye the two start trying to be the best that they can be, which results in them being completely artificial. They don't seem to understand that a documentary is unscripted and is supposed to be "real life." They may ask what their "character" should be doing in a scene or they ask to do "another take" when they stumble over their words. They may even ask "What's my line?" if they are too nervous to think. Maybe they aren't getting enough "screen-time" and their "character" needs a better personality so they crack bad jokes attempting to be far cleverer than they are in real life and failing. If the film crew is documenting a profession such as doctors or police while they are working an important case, expect the characters' antics to be to the detriment of their actual duties. Sister trope to Acting Unnatural in which a people told to "act natural" immediately find trouble doing so. Compare to Centipede's Dilemma in which when a person is unable to do a natural action after the fact that they do the action is brought to their attention.