While trying to figure out how this works, I missinterpreted the position of the dialog as: It is moved out of the way, so that I can see unobstructed, which folders are allready present.
The history.txt told me then, that it moves completely into the panel where the folder will be generated.
As there is a configuration already (wincmd.ini [Configuration] NewFolderOverPanel=0) the "move out of the way" could be offered as a selection.