What does steinbeck use most predominantly to create the dynamic between elisa and the visitor?

Which conclusion about pau amma does this excerpt support

Even the insistent cough of the woman next to him wasn't enough to draw his eyes away from the tiny type of the ancient book its pages were brittle and felt like they could crumble at the slightest disturbance he noticed the musty odor if each page as he carefully it over.

What is the central theme of the sniper