This picture is illustrates the anger many people have towards the current banking situation and employees of banking companies. There are many that believe that they are being mistreated by the banks. This picture uses rhetorical devices that parallels the opinion of the photographer. For example, the picture is taken in a alley, causing the frame to be small. This parallels the tight situation the man in the picture faces. Another device is the use of the cardboard sign. This indicates that he has very little money, and is fighting the banks because of it. The crowd indicates that there are a large number of people that have a negative opinion of banks and their employees. Finally, the expressions in the faces of the people illustrate pain and anger. This parallels their opinion.
http://www.nytimes.com/2011/09/25/opinion/sunday/whatever-happened-to-the-american-left.html?_r=1&ref=opinion