Glass Onion by The Beatles is a song that plays with the concept of layers of meaning and perception. John Lennon, who wrote the song, injects a sense of humor and irony, recalling various elements from earlier Beatles songs to create a sense of retrospection and self-referential commentary. The key themes include the complexity and obscurity of truth, playful misdirection, and a meta-commentary on the band's own image and the public's interpretation of their work. Noteworthy lines include 'The walrus was Paul,' which adds to the ongoing enigma and adds layers to the band's mythos.