not overly creative, but not all that bad for an on-the-spot performance
Have you ever been abroad and when discussing languages someone asked you to say something in your native language? One is always at a loss what to say in such moments. I think it's much worse with painting or any other creative art.
I'm a scientist but I, too, would have trouble to extemporize an article for the Scientific American or a similar magazine.
Luring someone into being creative might work. Forcing is not going to.