How has Steinbeck used imagery to describe Crooks’ room?

Imagery is description using the five senses of sight, sound, taste, touch, and smell.
We are visual culture, both in the 1930s when Steinbeck wrote and today, and Steinbeck uses primarily visual imagery to describe Crooks's room. Much of the imagery shows a contrast between Crooks's intelligence (and humanity) and how he is treated as little more than an animal because he is black.
For example, Crooks lives in a shed off the barn and sleeps in a long box of straw on which some blankets have been thrown. This shows that he is seen as little more than a beast of burden. Yet he has books in his room and owns a pair of gold-rimmed glasses to help him read. He also set up his room as a workshop, where he repairs broken animal equipment, also showing his intelligence.
Steinbeck offers a detailed description of Crooks's room. Part of it is as follows:

On one side of the little room there was a square four-paned window, and on the other, a narrow plank door leading into the barn. Crooks’ bunk was a long box filled with straw, on which his blankets were flung. On the wall by the window there were pegs on which hung broken harness in process of being mended; strips of new leather; and under the window itself a little bench for leather-working tools, curved knives and needles and balls of linen thread, and a small hand riveter. On pegs were also pieces of harness, a split collar with the horsehair stuffing sticking out, a broken hame, and a trace chain with its leather covering split. Crooks had his apple box over his bunk, and in it a range of medicine bottles, both for himself and for the horses. There were cans of saddle soap and a drippy can of tar with its paint brush sticking over the edge . . .