How does Tony Hillerman use imagery in People of Darkness?

Imagery:

"He was looking at a framed photograph on the wall behind the sheriff. It seemed to be a disaster scene, twisted steel wreckage in the foreground, a burned-out truck on its side, two men in khaki uniforms looking at something outside the frame, a police car and an ambulance of 1950 vintage. The scene of an explosion, apparently. A small white card stuck in the corner of the frame bore six typed names—all apparently Navajo. Victims, perhaps."

"The row of bare dead trunks now served as an incongruous landmark for a ruin that had otherwise almost returned to nature."