I am open to other possibilities but no one has ever suggested a different one than it being a five step pyramid. Instead most people simply refuse to even acknowledge most of these lines are parallel to the base because it doesn't fit their beliefs. I'm not sure they can even see them and I suppose they really can't.
If you draw a five step grid on the scan it fits like a glove for a hand. However the copyright holder specifically forbids drawings added to it so I can't post it.