How does Michael Connelly use imagery in Angels Flight: A Novel?

lmagery:

"Bosch couldn't put his finger on the look he saw on Kizmin Rider's face when he and Edgar returned to the squad room. She sat alone at the homicide table, her laptop in front of her, the glow of the screen reflecting slightly on her dark face. She looked both horrified and energized. Bosch knew the look but didn't have the words for it. She had seen something horrible but at the same time she knew she was going to be able to do something about it." Chapter 26, pg. 408

"He thought about Chastain and his final scream, a wail so loud and horrible as to be almost inhuman. It was the sound of fallen angels in their flight to hell. Bosch knew he could never allow himself to forget it." Chapter 40, pg. 594