My experience is with the MLVW Special Equipment Vehicles (SEV) office "box" and their penthouses. The SEV sits inside the ordinary truck box and the tailgate drops to access a conventional back door. The penthouse has a porch roof over the door and tailgate, a sloped roof for the stairs, and several flaps and wraparound baffles for light discipline, before transitioning to a modular tent end-section.
The blackout curtain photographed is much smaller than anything I have seen. So I had to remind myself of the layout of the Deuce and a Half shop trucks. Such a narrow tent made me wonder if there weren't expanded metal grill walkways around the truck. As for the truck at the link, this does not appear to be the case. So, is this blackout curtain just for the main door and tailgate?
http://olive-drab.com/idphoto/id_photos_m220.php