The book cover was designed to depict the themes, motifs and atmosphere of the novel and create an enticing cover. The image on the cover presents the hazy writing style of the author and the recurring events of the character seeing her double. The layout is also used to create pairs.

The serif font was chosen to present the traditional nature of classical music, which is a key theme in the book. The piece specifically referenced in the book is Rachmaninoff's Piano Concerto No. 2 composed in the 1900s, and thus the font was chosen to represent this period of time. The sans serif font balances the serif font, links the design to modern times as well as creates a clear distinction between the title and author information and the blurbs.

The color blue of the cover ties in with the name of the book as well as presents the theme and atmosphere of depression or "feeling blue" in the book.