Idea of the GUI is to provide useful visual interface to all the functionality of [vws] script.

So, there should be ability to start/stop/restart virtual machine, send keys which is impossible to send by pressing them on keyboard (because they are unconditionally handled by your X-server, window manager or something alike),
connect-disconnect removable devices etc.

Interface should look like dashboard, because virtual desktops typically have 4:3 aspect ratio, and most physical ones nowadays are 16:9. So vertical pixels are precious, and horizontal ones are plenty to spare.