How does Cynthia Ozick use imagery in The Shawl?

The imagery of nourishment is introduced in the first paragraph: thin, dry breasts; a hungry babe; a walking cradle; tiny lips sucking air. Rosa's mother-love forces her to give to Magda beyond her physical and emotional capabilities. She has become lighter than air, a "floating angel. . . teetering on the tips of her fingernails." She is in a trance-like state, a state in which one's intellect is suspended and one's instincts take over. Rosa never considers her own needs but lives only for her child.