How does Mariano Azuela use imagery in The Underdogs a Novel of the Mexican Revolution?

Imagery:

"They ate voraciously: then, glutted, lay down on the ground, facing the sky. They sang monotonous, sad songs, uttering a strident shout after each stanza."

"'Thank God, a kind soul and tortillas full of beans and chili are never lacking,' Anastasio Montanez said with a triumphant belch.
The mountaineers would shake calloused hands with the travelers, saying:
'God's blessing on you! He will find a way to help you all, never fear. We're going ourselves, starting tomorrow morning. We're dodging the draft, with those damned Government people who've declared war to the death on us, on all the poor. They come and steal our pigs, our chickens and corn, they burn our homes and carry our women off, and if they ever get hold of us they'll kill us like mad dogs, and we die right there on the spot and that's the end of the story!'"