I drew Pinkie Pie straddling an imaginary machine (mostly ended up invisible because drawing mechanical stuff is hard). But anyway, an idea occurred to me. If someone can guess what that invisible machine is, I will offer a free picture.
The prize picture will feature no more than 3 characters, will be in color (possibly with shading), and otherwise my usual guidelines will apply content-wise. (I'm usually pretty flexible with what I'm willing to draw, but if you're not sure, feel free to ask)
Make your guess either in the comments here or in reply to the pic itself. In the event that multiple people guess correctly, the prize goes to whoever gives the correct answer first. Good luck!