The first time the space metaphor appears is early in the story, when Howard is first disappointed with the routine nature of his job: Howard's "shoulders slumped and he could feel a space widening in his rib cage." Having seeded the story with this image, Ochsner works with it until it seems to signify something transcendent, a state of being without boundaries that is quite the opposite of little Howard's constant petty fears and imaginings.
The Necessary Grace to Fall