What are window shades?
In some way, they are almost a form of iconisation, except that the window border that acts as an “anchor” for the window remains and it is not a representation, but an actual window as a result: only rolled up. This means that normal window operations can still affect this window as a normal window would be affected. (As a sidenote, try using the window shade, and then iconising it–it will de-iconise in its rolled up form factor.) The window shade may be rolled up in any direction that the window shade button is anchored against. In the default theme, this means that terminal windows will roll “up” sideways, while non-terminal windows roll upwards, as the buttons are on the left and top sides, respectively.