How does Stephen King use imagery in Wizard and Glass?

Imagery:

"He stood on what appeared to be nothing, legs apart, his right hand on his hip and his left on the sandlewood grip of his revolver. He stood as he had so many times before, in the dusty streets of a hundred forgotten towns, in a score of rocky-cannon killing zones, in unnumbered dark saloons with their smells of bitter beers and old fried meals. It was just another showdown in another empty street."

"He (Roland) fetched a sigh — the deep sigh of a man who contemplates some arduous piece of work — and then tossed fresh wood on the fire. As the flames flared up, driving the shadows back a little way, he began to talk. All that queerly long night he taled, not finishing the story of Susan Delgado until the sun was rising in the east and painting the glass castle yonder with all the bright hues of a fresh day, and a strange green cast of light which was its own true color."