Final answer:
The presence of unread, brand-new books in Gatsby's library suggests that he isn't what he appears to be.
Step-by-step explanation:
The presence of unread, brand-new books in Gatsby's library suggests that he isn't what he appears to be. This detail highlights the facade that Gatsby has created for himself, as he wants to give the impression that he is well-read and educated. However, the fact that the books remain unread implies that this aspect of his character is merely a show.