For an Ellipsoid shape, we need the minimum Height and Width of the innermost "ring" of Dock
Items. Note that these can not exceed the dimensions of your screen.
As you adjust these values, the background will also be changed so that the aspect ratio of the
background matches the aspect ratio of the innermost ring.
Normal Ellipses' greater axis is usually the horizontal axis (or width), however you can set the
width to be less than the height if you wish.
