Circles are predominately used to form the art within this world, the natural world itself (Note how the storm clouds in an early scene are tangled masses of thin, swirling lines of various shades of gray), and frames to outline characters and scenes (notably a shot of the witch's owls, which are designed with round heads, attempting to crack a circular
window and another showing the orb of the witch's eye
fitting neatly into the outlines of a eye - shaped peephole).