The shot of the car driving away reflected in De Niro's glasses in Casino has been repeated over and over again, as has the close-up on the peering eye in Psycho.
Movies build upon each other with references all the time - the reason so many horror movies show us slow moving shots from the killer's POV is because Friday the 13th did it so successfully, for example. Aside from literally adapting works in other mediums, film is full of homage, parody, send-ups, and tributes - and it loves to self reference most of all. The medium most fascinated by intertextuality by far though is cinema. It began in literature, but has since been used in theatre, music, painting. Essentially it means taking an idea - an image, a line, a theme - and deliberately transplanting it from one piece of media into another. Intertextuality has existed in media for centuries.
