The cover of 'To Kill a Mockingbird' is a powerful representation of the book's themes of racial injustice and the loss of innocence. It features a simple yet evocative image of a mockingbird in a cage, symbolizing the oppression and confinement faced by the characters in the story. The use of muted colors and subtle details creates a sense of melancholy and reflection, inviting readers to delve into the profound and thought-provoking narrative of Harper Lee's masterpiece.