How does Jack Gantos use imagery in Hole in My Life?

Imagery:

"I just couldn't believe how ugly I was becoming. At first I was horrified. It was as if I had contracted a disfiguring disease that was slowly but surely reshaping my face. Huge lumps heaved up under the skin. Blemishes surfaced. Brown marks appeared as if I were rotting fruit."

"Stoned out of our minds, we navigated through the long madhouse days of the voyage as if crossing the ocean in a floating sanitarium."