Da Vinci shows us in his drawing humanity, science, discovery, empathy, light, and beauty. All can be metaphors for life. This an offshoot discussion from my article, The Cult of Oblivion: CIA, Abstract Expressionists, and Kant.
Ellipses: Don’t Start a Still-life Without ‘Em by Michael Newberry
Ellipses make or break any drawn plate, glass, or bottle. When beautifully done they transport the viewer to experience serene harmony. It’s rare not to have a man-made cylindrical object in a still life.
It should not be surprising that da Vinci painted/drew beautiful ellipses. This detail is a from The Last Supper–it is the plate in front of Christ.