Because it has squares for sides that meet with three or five in the corners.
Meet my new crocheting project, a regular twelve-sided polyhedron in disguise…
The advantage of this missing part is that you can turn the whole thing inside-out, like here. In this picture you can clearly see a five-corner and a three-corner. The yarn I used changes color every 30 cm or so, giving these nice stripes.
How is this a dodecahedron you ask?
Well, take a corner where five squares meet, and draw a pentagon around it. It consists of five triangles, each one-half of a square. You can do that on every ‘five-corner’ of the bowl (including the one that’s not there), none of the pentagons will overlap, and there are twelve of them.