While these thumbnails enable you to preview the content of a minimized folder and also distinguish between applications more easily, I'm not sure if MiniMIZE is really that better than the Windows taskbar itself. If you're anything like me (right now I have 12 minimized elements) you'll cover your entire desktop with thumbnails. Also, once you open any app or folder in full screen, you'll lose track of the thumbnails unless you mark them to be permanently on top, in which case they'll inevitably take a lot of room.
The aim behind MiniMIZE – that is, provide an easier way to manage minimized windows – certainly deserves credit, but they way it has been implemented needs serious improvement.
With MiniMIZE you can turn minimized windows into thumbnails and move between them more easily.