How does the author use imagery in the novel, Theo?

Imagery:

At first Theo heard footsteps behind him, but he did not look back and the sound faded away. He crouched in a recess under a balcony, beads of sweat pouring down his face, trying to catch his breath. No cracked skull, no broken bones, he thought, worried at what might have happened had he been caught.

Theo left his hiding place through a narrow street leading to the puppet theater where he had performed with his godfather. It was boarded up, but he stood on a stone and peered through an opening near the top of the gate into a small courtyard, eerily silent; his godfather was off to war. The only sound was the chatter of a cricket in the yellow gorse that proliferated in the yard.