How does Annie Dillard use imagery in An American Childhood?

Examples of Imagery:

"Every woman stayed alone in her house in those days, like a coin in a safe."

"In the leafy distance up Edgerton I could see a black phalanx. It blocked the sidewalk; it rolled footlessly forward like a tank. The nuns were coming. They had no bodies, and imitation faces. I quitted the swing and banged through back door and rain to Mother in the kitchen."