one of the things about shadows of stationary objects that fascinates me is how much they change with the movement of the sun (or other light source). one normally expects a shadow to resemble the object which is casting it, at least to the degree that it is recognizable. however especially when the sun is low it can create amazing distortions.
if you had only seen the shadow and not the object, could you have determined that this was from a picnic table? what else could it possibly be?