How does John Boyne use imagery in The Boy in the Striped Pyjamas?

Imagery:

"He walked slowly towards it, hoping that from here he might be able to see all the way back to Berlin and his house and the streets around it and the tables where the people sat and drank their frothy drinks and told each other hilarious stories. He walked slowly because he didn't want to be disappointed."

"But she was still watching from the window and this time she wasn't looking at the flowers or the pavement or the bench with the plaque on it or the tall fence or the wooden telegraph poles or the barbed wire bales or the hard ground beyond them or the huts or the small buildings or the smoke stacks; instead she was looking at the people."