Intertextuality is a term to describe when films borrow from each other such as mise en scene, camera angles, sound or editing. You may recognise these technical areas in a certain film which has been used before from another film. The director can be influenced or inspired by another directors work so there fore they may use a certain scenes for their film.
The film Psycho was a very popular film for its famous shower scene where the main leading actress was murdered in the bath tub by being stabbed mutiple times. You can see from many other thriller films have borrowed some elments from Psycho to use in thier films. The Step Father used a knife to kill his victim in the bathroom just like Psycho and when the bath cutains was dragged down it made the audience think back to Psycho. Another film is What Lies Beneath has similar aspects such as the women lying in the bath tub while the water is running.