Elements of fiction include character, plot, atmosphere and setting, language, point of view, theme. It is difficult to differentiate plot from character in writing an essay about a short story. In considering plot, look at the conflict that exists in the story. Ask yourself which central conflicts drive the plot. Conflicts in short stories can be internal or external.
Internal conflicts revolve around self versus self.
The answers to these questions can act as a working thesis. Read and reread the details of the short story to make connections to support that single point, your interpretation. The more connections you find, the more fully developed your essay will be. That is, do not give meaning to passages from the story independent the thesis they support. If you do a Reader-Response, do not write an interpretation of yourself.