William Faulkner's "Barn Burning" is filled with images of objects being destroyed, usually at the hands of Abner Snopes. He is an angry man and an arsonist, who takes out his frustration on those around him, particularly those in power since he has none. The scene where he visits the de Spain household is very important in many ways. When Abner and his son, Sarty, walk up to the house, Sarty notices his father deliberately stepping in horse manure. Though he doesn't understand why at first, he later does, when he sees his father step onto the de Spain's expensive, white rug, tracking manure wherever he goes. His father rudely ignores the servant, intent on making his 'mark' in that household. 

In doing this, Abner is showing defiance and anger toward this family who has money and power, where has neither of these things. He also reveals a disregard for rules or what is right or wrong. In this key moment, Sarty realizes that his father will never change and that he will continue to destroy people's belongings and burn barns. It is a pivotal moment for him and lays the groundwork for the final scene when he tells on his father.