If your dodecahedron were essentially your “resume”, you’d go out of your way to keep it safe from thieves. Besides, stealing one wouldn’t do you much good, as you’d be discovered as a fraud pretty quickly based on the quality of your work.

Having one of these in your possession would be enough to get you in the door, as well as giving your potential employer a quick and easy way to judge the quality of your work. The alternative would be to require a prospective employee to make a dodecahedron in front of you, which doesn’t really provide all that much of a benefit in the long term.