As a kid, it might have been the box from the new refrigerator your parents bought. At some point, we've all made a fort/hiding spot or something out of a gigantic cardboard box.
Now that you've grown up, HBO has come up with another use for the gigantic cardboard box. As a college student with roommates, you've probably been distracted when trying to watch one of your favorite shows. So HBO is giving college students giant cardboard boxes that you basically sit or lay inside, so that you can watch/stream in peace.
If you're interested, you need to hurry as today is the final day to enter to get your own HBO Box.