In My Life as a Book, illustration is both a recurring and multi-definitional symbol and a motif for Derek’s character and the plot that unfolds over the summer. Derek has an aversion to reading books without pictures, and his teacher wants him to learn new vocabulary to help make reading easier. Derek decides to draw, rather than write, the definitions of each word he learns over the summer. These drawings come to serve as a showcase of his life experiences at Learning Camp, his interactions with his family and friends, and his investigation into Susan James’s death. Through illustration, Derek bonds with his father, a professional illustrator. Derek learns a lot from accompanying his father to his workplace and helps motivate his father to try a new animation program and break out of his rut.

Each of Derek’s illustrations is a unique symbol for the word it defines. For example, he depicts the word “organize” as a stick figure on a ladder, placing objects neatly on a shelf, and he draws the word “unfamiliar” as a man peeking around a corner, scared, as he sees a stranger approaching. Some of Derek’s illustrations are more literal, such as his drawing of the word “slobber,” which is Bodi’s long tongue drooling onto the floor as Derek stands by in disapproval.