It's not the packing itself, of course. The big thing to get packed around here is books, and that's pretty easy stuff, a little spatial jigsaw puzzle, accompanied by a small but rosy glow when you manage to get the exact proportion of paperback to hardcover and the box fits together into a neat solid without any awkward square holes or narrow canyons just a smidge too short to wedge another paperback. Sometimes it doesn't work, and you have to wedge a stuffed wombat or a bookend into the aforementioned holes. (Candles fit in there pretty well, but I gave up on candles awhile back, realizing that no matter what current decorating wisdom may be, the only time I considered candles appropriate was in the middle of a blackout.)
No, the disorienting bit is the bare walls, the bare bookcases. We get used to the topography of our rooms, no matter how cramped and cluttered that may be. We project ourselves into them. Humans have a wonderfully malleable sense of body space, as anybody who's driven a car can probably attest. We expand our mental space to fit. For awhile, our brain is willing to graft the car onto our personal space. Our sense of self extends out to the bumpers. If somebody tailgates, we feel as annoyed and cramped as if they were standing an inch away, possibly more so--if somebody's standing an inch away, we get confused, whereas if somebody's tailgating, we KNOW they're an asshole. How often, when doing a tricky bit of parallel parking, do we say "How does the car look over there?" compared to "How am I lookin' over there?" Our sense of what space we are occupying is gloriously stretchy in that regard, and routinely encompasses our clothes, our vehicles, our weapons. (Considering this, I can easily imagine an alien species that would be congenitally bad drivers, lacking the malleability of mental projection. They probably wouldn't be too keen on clothes, either.)
To a lesser extent, I think that happens in the house. Not to the same extent--if a car drove into the house, I wouldn't yell "That bastard hit me!" the way I would if a car drove into my car. (I would yell many other things, most of them not suitable for mixed company, mind you.) But still, the altered topography of the house has a kind of mental echo. I look up, expecting to see a plaster fish and a tower of DVDs, a wall of multicolored paper spines, and I see a bare wall and a bare bookcase, and I feel a little unsettled, as if the blank spot is inside my head, too.
I could go for the cheap metaphor and compare these mental holes to missing teeth, but it's not quite right. If you've got a hole where a tooth used to be, you're poking it with your tongue approximately once a nanosecond. These bare spots are tricky. Once I'm not looking at them, I almost forget they're there, and then I look back, and wham! once again, bare plaster, bare bookcase.
It's the missing that's troubling. The stacks of boxes in the bedroom don't bother me nearly so much. That's just extra. I could learn to manuever around them, if I had to, clambering over them to get to bed. People can learn to live with nearly anything. We're an adaptable bunch, which at the extreme end gets us into trouble, and we wind up with the people who have five hundred cats, half of them dead, in one house, or a jungle of newspapers and KFC tubs, or a live goat. A little less adaptibility, in some cases, might not go amiss.
Once the art comes down, the house will REALLY feel weird. I'm avoiding it until the end, because that's the tipping point where suddenly this isn't home anymore, it's just a hotel room with a lot of boxes in it, and then we'd go from "disorienting" over into "depressing." The art holds the walls at bay, which is a function of art that I think we tend to forget about on the production end. I can't say it's the most important function of art, but I can't say it isn't, either.
Anyway! Enough maundering, more packing!