Grab any resizeable window in GW (party window for example) and start resizing it. At some point it will reach its minimun size, dut don't stop there. If you continue the window will start moving upwards or some other direction. Now if you so called resize-move that window far enough and then grab the title bar to actully move the window as you would with any other, you would notice that cursor snaps to a different location and the window acts weird when you try move it.
Here it is in action.
