A square waffle shape is included as well as a sandwich tray for triangular sandwiches. The problem with this is that by cutting the sandwiches into triangles at an angle, the space for the filling is extremely limited. So more than one slice of ham and one slice of cheese won't fit.
Tip: The shell-shaped troughs are much better. This way you can also put filling in the middle of the bread slices, and the bread is only "welded together at the edge to form a perfect pocket" like a ravioli. Ideal for e.g. mushroom ragout, pasta sauce from the day before etc.