As they said it saves info about a given directory/window. This is saved between reboots so if you go to a directory, do Show All, arange the icons as you want, and do Snapshot, the next time you power up and go to that directory the window will look the same.
So far it doesnt seem to work on the top level very well, whether or not WB is Backdropped. It somewhat records the icons positions and seems to take the Show All there and apply it globally, but the icons do still move around somewhat after reboots. Not quite as randomly though.
PS this all works better without flicker fixers, so if you want to send me your board...
