Diegesis

Diegetic – Joker (2019)

Reddit spotted Batman in the very first scene of Joker. Did you catch it? |  Hollywood - Hindustan Times

The impact this scene from the Joker has on the audience is very powerful. The close up on Arthur in the mirror roughly manipulating his smile makes the audience feel uncomfortable and tense, just as Arthur is feeling. The director emphasized this by blurring everything in the foreground and background directing us to only look at Arthurs actions.

Intra-diegetic – The Blair Witch Project (1999)

Weekly Horror: The Blair Witch Project — Penn Moviegoer

The Blair Witch Project uses “found footage” which allows the audience to feel as if they are really there with the characters behind the camera, they are part of the story. The impact this technique has on the audience can truly be terrifying especially when used in a horror film. The camera work makes the audience feel tense and engrossed in the action on screen.

Extra-diegetic – American Psycho (2000)

American Psycho Ending: What Really Happened? | Cinemablend

In this scene in American Psycho, Patrick is staring straight into the camera and into the audiences eyes while talking about what he is thinking through a voice over, this is creating a relationship between him and the audience, which is quite jarring when watching the film.