I normally leave other people to deal with the Physics of Anime, as it's usually the little things that catch my attention. (Not always though, as this RxJ post proves...) This time, it's the vanishing futon cupboard (or rather, cupboard space) in Kirino's room.
Firstly, a note on "traditional Japanese rooms", which Kirino's used to be. The cupboard in which Kirono stores her stuff seems to be one of those deep sliding-door cupboards, which you'll be able to find if you stay in a Japanese-style room at some Japanese hotels/ryokans.
As you can see in the picture above, they usually look like they're built into the wall (or there's another part to the cupboard so that it spans one side of the room, wall-to-wall). What's a bit more difficult to discern is how deep it is: they're about one metre deep, as Japanese people normally fold their futons (aka thin mattresses) and store them in that space. That's why I call it the "futon cupboard".
Taking a look at Kirino's room then, we can see that there's about 15-20cm (6-8in) between her door and that cupboard. (If you watch carefully, you'll also see that the cupboard in front of it changed positions several times during the course of that first consultation session - changes that can't be attributed to differences in perspective. But since it's a cupboard on wheels, I assume that Kirino and Kyosuke just moved it at various times...)
However, if we look on the OUTSIDE her room ('scuse the dimness of the screenshots), at first, there seems to be a larger space between the edge of her door and the corner - looks like ~25cm(10in) to me. And then the corner and perpendicular wall disappear altogether in the next pic.So...where in the world did that space disappear off too???
Whilst we're on this topic...when I was in Japan, I did precisely what Kirino has done - that's to say, shoved a book cupboard into the back of my futon cupboard and stacked DVDs etc in front of it - though for different reasons. Not only was I running out of shelf space in my apartment, but all the stuff I had outside was turning yellow/pale in the sun, including a really nice Johnny Depp clear file that my teacher had given me!
More Bakemono probably this weekend.