When checked, this feature allows your EBW1150's screen to show the "Bookshelves" i.e. folders within your GEBLibrarian's directory in your computer, thus allowing you to navigate between those bookshelves so as to get to the ebook that you want to transfer....
(breathe)
Then just click that ebook and wait for it to be transferred to your EBW1150's memory (external memory
aka SM card, if installed).
Does it work "as advertised" (above) for you?