Four circles or diamond shape? optical illusion

Is it a diamond-like shape or four circles? Rotating it or viewing in the mirror shows something else! Based on math by Kokichi Sugihara. Best viewed at 45 degrees angle.

Includes a rotatable figure+support, or a smaller to place directly on a flat surface.

My other illusions: https://www.thingiverse.com/Matsemann/collections/matsemanns-ambiguous-cylinders
The code & stuff: https://github.com/Matsemann/impossible-objects