How does T. Coraghessan Boyle use imagery in The Underground Gardens?

Imagery:

As a boy in Sicily he stood beside his brothers under the sun that was like a hammer and day after day stabbed his shovel into the skin of the ancient venerable earth of their father’s orchards. As a young man in Boston and New York he burrowed like a rodent beneath streets and rivers, scouring the walls of subway tubes and aqueducts, dropping his pick, lifting his shovel, mining dirt.

When he got down off the train, the air hot and sweet with the scent of things growing and multiplying, he was so filled with hope it was a kind of ecstasy. There were olive trees in California, orange and lemon and lime, spreading palms, fields of grapes and cotton that had filled the rushing windows of the train with every kind of promise. No more sleet and snow for him, no more wet feet and overshoes or the grippe that took all the muscle out of your back and arms, but heat, good Sicilian heat, heat that baked you right down to the grateful marrow of your happy Sicilian bones.