How does Roald Dahl use imagery in James and the Giant Peach?

Visual Imagery:

"Inside, James could see a mass of tiny green things that looked like little stones or crystals, each one about the size of a grain of rice. They were extraordinarily beautiful, and there was a strange brightness about them, a sort of luminous quality that made them glow and sparkle in a most wonderful way."

"But the peach ... ah, yes ... the peach was a soft, stealthy traveller, making no noise at all as it floated along. And several times during that long silent night ride high up over the middle of the ocean in the moonlight, James and his friends saw things that no one had ever seen before."