How does Margaret Atwood use imagery in The Robber Bride?

Imagery:

"If she were six feet tall and built like a blockhouse; if she had hips. Then she'd be threatening, then she'd be an Amazon."

"Their love is gentle and discreet. If it were a plant it would be a fern, light green and feathery and delicate; if a musical instrument, a flute. If a painting it would be a water lily by Monet, one of the more pastel renditions, with its liquid depths, its reflections, its different falls of light."