With a few exceptions, such as hamburgers and hot dogs, sandwiches are cut before serving. Cutting serves two purposes: It makes the sandwich easier to handle and eat, and it makes possible a more attractive presentation.
The first purpose is usually accomplished by simply cutting the sandwich in half or, if it is very large or thick, into thirds or quarters.
The second purpose can be served by displaying the cut edges rather than the crust edges to the outside. If the sandwich was neatly made of good ingredients and tastefully garnished, it will be appetizing and attractive. Little purpose is served by cutting and arranging the sandwich in complicated ways.