In the movie The Black Dahlia, with Josh Harnett, there is a scene where Hilary Swank's character invites him to dinner at her home. The actress playing Hilary's mother has a plate of food in front of her. When the camera closes in on her, what appears to be potatoes is on the left side of the plate, when it closes in on her again they are on the right. They go back and forth for about 3 or 4 times.