How does Richard Peck use imagery in The River Between Us?

Imagery:

"The paper was loose and peeling on the walls. I wondered how many layers you'd have to scrape away until you came to the time when these old people were young."

"Her conversation was a lacework fan that opened and closed, concealing and revealing."

"I caught a glimpse of happiness, and saw it was a bird on a branch, fixing to take wing."