the angelic man who understands the purity of shoes.
(this page discusses the prohibition of tying and untying knots and if they apply to shoes. or just the type of knot that a professional shoemaker would use in the actual making of the shoe, that is not designed to be undone by an ordinary person. so, a drawing of a maolo blahnick shoe with a knot as an integral part of the design. When discussing sandals, there is a debate about different types of broken straps on a sandal, if they make it an unusable object, and therefore cannot become ritually impure and is therefore considered pure. Hizkiya is so impressed with his student, R. Yochanan's reasoning that he considers him like an angel, or the ideal man. for english translation of this talmud page, see here)