I think Fitzgerald uses much to bring out characterizations of his characters. One way is through situational decisions. Fitzgerald uses individual actions in specific moments to reveal much about his characters. For example, Jordan cheating in golf is used to reveal her amoral characterization. It is a singular moment, but it is something that resonates in the mind of the reader as a part of her characterization. In this moment, her character is brought out and is impossible to dismiss. Tom's spouting of racial fear and hatred is another such moment. It is through this action in which the reader understands much about his character from a specific moment. Daisy with the shirts is yet another instant in which an action is used to evoke so much in a character. The use of singular actions are employed to bring out much in characterization. Fitzgerald recognizes that more can be revealed through actions than mere words. Seeing Tom lie or abuse another or seeing Daisy waffle in her emotions or seeing Gatsby pursue something that is impossible are all actions in which the art of characterization is developed. It is also a technique in which the purest understanding of who these characters are and how they function can be revealed.