Mise-en-Scene

This is a shot of when Bud White first goes to Pierce Pratchett's house to speak to him about Lynn Bracken. In this shot, there is a clearly defined divide between the two. The wall between them shows the moral difference. Bud White is an officer who is aggressive against men who abuse women, while Pierce Patchett runs a prostitution ring. They are on two opposite side of moral standards, and are on two opposite sides of that wall. Furthermore, White is much larger in the frame than Patchett, as White is standing on a walkway above him. This also illustrates his moral high ground over Patchett. He is physically looking down on Patchett, just as he would look down on his line of work. 

Another interesting aspect is the color of the frame. Patchett is surrounded by green grass and trees, while White stands in a sea of grey concrete. Perhaps this could describe each character's life at this point. Patchett is living well, has a nice property and obviously has free time. White on the other hand just lost one of his friends and the police department is in turmoil. White probably sees that the grass is greener on the other side of the law (also that there is any grass at all).