This is Sep. Stomping off. He had wanted the big spade his brother was using, but Lev said he couldn't. So he walked away. Angry. Towards the sea. Now and then looking backwards if anyone was watching him. Just in case.
I'm not familiar with the book, but the image portrays a mood of aloneness and solitary-ness (not really words, I guess). Love the use of negative space.