This scene is a reference to the 1929 film Un Chien Andalou! It's a surrealist film directed by Luis Buñuel and Salvador DalÃ. I don't remember the entire film, but I do remember being creeped out by it. 😱😨
(Let me know if the still from the film is too disturbing, I'll be more than happy to just switch it to the text from the book!)