Everything in the settings becomes symbolic. For example, Kilgore Trout leaves wet footprints on the hotel carpet, which are taken to mean "I have been here". It is a symbol of his role as an artist, just before he is to speak at an arts gala for the first time.
Every sign by the road and every object in the story has a symbolic meaning which is explored by the author in long sidebars that go nearly painful detail. This lesson explores the theme of the role of an artist as a describer of the universe.