It is nothing more than the station right after the flash used to press or smooth out the fibrillation and texture of the base print. Automatics can install a roller where the squeegee goes, I use a Teflon sheet taped to the underside of a blank exposed screen on the manual. If you can time the flash just right where it's not too cured but just enough it's not sticky, immediately after flashing, swipe over it with the crush screen and it does improve the final print.