How does Ann Patchett use imagery in The Magician's Assistant?

Imagery:

“If someone were to have pressed a sheet of glass down over the top of Alliance, Nebraska, in winter, it would have resembled an ant farm. Everything was a tunnel eaten neatly, carefully into the snow. The tunnel of the streets branching into the narrower tunnels of driveways and carved-out sidewalks. The snow banked over cars, lawn furniture, porches, like frozen animal carcasses stored for future need.”