Jean-Leon Gerome's portrait in the studio, where he is sculpting Tanagra, which holds a miniature of Dancer With Hoop and, on the far left, a bust of Selene
The reason why the Pantheon is so great is that the giant dome of concrete would collapse if not for the square reliefs acting as "miniarchs" offloading the weigth uniformly. Such genius architects and yet we know pretty much nothing about them