how does steinbeck's description of the atmosphere inside the barn reflect the action as is unfolds, especially leading up to the discovery of Curley's wife's body?

This scene is a calm before the storm. The barn is peaceful inside. There is plenty of new hay and the horses are nibbling away. There is the soft light of the sun that filters through the walls of the barn. It is a setting that might resemble the dream farm that George and Lennie want. It is similarly peaceful outside the barn,

From outside came the clang of horseshoes on the playing peg and the shouts of men, playing, encouraging, jeering. But in the barn it was quiet and humming and lazy and warm.

 Lennie’s dead puppy interrupts this peaceful scene. The puppy is a precursor or foreshadows death to come. The arrival of Curley's wife into the barn intensifies the atmosphere.