Eight shapes built in code rather than loaded, which is Blender's Add Mesh set minus the monkey. Each one hands back the same kind of thing a loaded model will, so nothing downstream knows the difference.
They are kept under a name made from their size, so asking twice for the same size gives back the same shape. Look at the two balls: the globe-style one bunches its triangles at the poles and the other does not, which is why there are two.