What effect does Hemingway's limited use of adjectives have?

Hemingway's limited use of adjectives enable us to understand the story at two levels. The first level is that the simplicity makes it easier for us to understand the text itself in its physical form. The second level is the deeper meaning which is reflected in the minimalistic style. Instead of just telling us something, he wants us to understand it on our own, making it a much more lasting impression.