How does Alice Walker use imagery in The Color Purple?

Example of Imagery:

“Man corrupt everything, say Shug. He on your box of grits, in your head, and all over the radio. He try to make you think he everywhere. Soon as you think he everywhere, you think he God. But he ain't. Whenever you trying to pray, and man plop himself on the other end of it, tell him to git lost, say Shug. Conjure up the flowers, wind, water, a big rock.”