I am still not sure what "different shapes" refers to - the first thing it made me think of was the different lozenge and other assorted shapes on the tails of carrier aircraft later in the war.
But then I wondered if it referred to different shaped stripes - such as straight across, diagonal, or inverted-v types of stripes.
I really wish my eyes weren't this bad - I look at photos where people say you can tell the different colors from the shading, and I can barely see the shading at all!