Luis Buñuel told Salvador Dalí about a dream in which a cloud sliced the moon in half "like a razor blade slicing through an eye". Dalí responded that he'd dreamed about a hand crawling with ants. Out of these two dreams this film was born.
During the bicycle scene, the woman who is sitting on a chair, reading, throws the book aside. The image it shows when it lays open is a reproduction of a painting by Vermeer. Vermeer was a Dutch painter greatly admired by Salvador Dalí, and whom Dalí referenced often in his own paintings.
David Bowie began every concert in his 1976 "Station to Station" tour by showing this film. (If you've ever heard an audience groan at the opening scene, imagine an entire auditorium, most of whom were undoubtedly seeing it for the first time.)
In 1960, a soundtrack was added to this film at the direction of Luis Buñuel. He used the same music which was played (using phonograph records) at the 1929 screenings - extracts from "Liebestod" from Richard Wagner's "Tristan und Isolde" and two Argentinian tangos.
On the album "Doolittle" by The Pixies, the song "Debaser" is based on this film. Repeatedly throughout the song, the line "I am un chien andalusia" can be heard being screamed by the lead vocalist, Frank Black.