What are the motifs in Ghost World by Daniel Clowes?

Lack of authenticity is a motif through the story.The book suggests that most people and institutions are in some sense inauthentic or fake. The most obvious example of this is the 1950s themed diner Hubba Hubba. When Enid and Rebecca go there they immediately criticize it for not being authentic. Enid comments that their waiter's hairstyle is not from the 1950s and doubts that people in the 1950s called desserts "mind-benders" as the menu does.