As of this afternoon, the gesture drawing tools will make an attempt to resize each image to be as large as possible and still fit on your screen without scrolling. With a little extra legwork, I got it working in mobile safari as well, so you iPad users should have a much nicer experience!
Other minor changes included the addition of a drop shadow on the "time left" text, so you can see what length of pose you're drawing even when the image has a white background. Also, when you pause, the word "paused" will remain on-screen until you unpause.
More to come. For now, happy drawing! :)