In order to change the aspect ratio of the little zoom box (by changing the height of the big zoom box), I have to do two things: move the top bar up, then move the bottom bar down to get the wrist guard out of the way. I don't use the wrist guard at all (I rest my wrist on the table), so I don't want to adjust its size. It would be much, much better if the default was that the top bar moved independently of the bottom bar, so that I could enlarge the zoom box in one gesture rather than two.