I was watching a you tube clip of it and even though assimilation had not been added to the storyline at this stage it's really the only thing that makes sense to me. Why else would they cut a section out of the crew quarters? Theres no valuable technology there.
I assumed that because the tractor beam seemed really tight around the cut out section it was also acting as a forcefield keeping the air in.
I can just imagine some poor bastard walking into his living room after a shower and suddenly his quarters are in space surrounded by a forcefield being sucked towards some giant borg cube