In this film’s first minute, a man and a woman calmly get together so he can nonchalantly slice open one of her eyeballs with a razor. In the remaining fifteen minutes of Luis Bunuel and Salvador Dali’s surrealist classic you get pianos with dead donkeys plopped on them, a mysterious severed hand laying on a busy sidewalk, a man who literally wipes his mouth right off his face, and at least a dozen more bizarre images that mostly take place in a small French apartment over several years. 
It’s aggressive nonsense. It has no story. Don’t look for one. The best summary I can come up with is that it’s about a man and a woman arguing, but that still doesn’t quite cover it. Bunuel and Dali always maintained that the only point to the film was complete irrationality. If an idea made sense, they didn’t use it. It started with dreams. Bunuel told Dali about his dream in which a cloud moved across a full moon in a way that suggested to him a razor cutting into an eye. Dali told Bunuel about his own dream of a human hand covered in ants. For two young surrealists (Dali was 24 and Bunuel was 28), those images felt like a good start for a film.
Today, it’s a college film course classic and likely the most widely seen, talked about, and referenced short of the silent era.