This is "The Tortoise Tamer," a 1906 oil by the Turkish Romantic painter/archaeologist Osman Hamdi Bey. It's true that turtles are trainable; here's a sweet amateur blog post on how one does this, complete with videos. Yet this piece is meant to be an allegory on his slow and steady work pace (which got a lot of good work done), as well as harking back to the ways turtles have been brought into pleasant use over the years. I'm not counting turtle soup, and thankfully neither did he.
Osman Hamdi Bey was the subject of a graphic novel a few years ago. Have a preview of the book and its creators here.