Psycho
Not sure if the title gives it away, but Psycho is a real psychological thriller brought to us by none other than Alfred Hitchcock. One of those most daunting scenes is when secretary Marion Crane, played by Janet Leigh, accompanies Norman Bates to his home after dinner, where she will have her famous shower. Bates watches on through a peephole that is disguised with a painting.
What is the painting of you might ask? It depicts a biblical trope of Susanna and the Elders whereby a woman is being spied on whilst she is bathing by two men. In true Hitchcock fashion, during the movie’s trailer, he can be seen walking around the motel pointing to the painting and saying “This picture has great significance because–” and just doesn’t finish his sentence. I guess genius’ can be weird like that.