How does Robert B. Parker use imagery in God Save the Child?

Imagery:

"Besides the white linen jacket, I had on a red checkered sport shirt, dark blue slacks, and white loafers. Me and Betsy Ross. I was neat, clean, alert, and going to the back door. I rang the bell. Ding-dong, private eye calling."

"I poured the water on her head. She screamed and stepped back. She opened her mouth but nothing came out. The relief was wonderful."