In the story "Hills Like White Elephants", what do the main characters in the story look like?
Hemingway does not give details about the appearance of either character. The most we are told is that it is an American and a girl, and that the girl was wearing a hat - a detail that says more about the time period than it does about the girl herself.
The reason that Hemingway does not give details is very specific. Hemingway was a modernist writer who believed in simplicity. Unlike the authors who came before him, Hemingway's style used a lack of detail and a lack of wording in order to get his point across. This is known as imagist writing - the simple images and words provided are meant to convey emotion. The emotion in this story is that of conflict, and of ambiguity. The girl and man are at a crossroads and don't know how to communicate about it to one another, much less how to proceed. That uncertainty is echoed in our ignorance of their past and their appearance - even their names.