It's an extraordinary clever advertising campaign; you've got the cute and amusing cats exploring Ikea, showing Ikea products off with the tag line "Happy Inside," and then you've got the "making of video," which has helped make the actual commercial become very popular in short order. I suspect that part of the intention by the very expensive (and newly hired advertising agency) was to have the commercial go viral. It hasn't done that, but I suspect the success of the commercial in terms of popular appeal will encourage other agencies to do similar "dual video" releases.
The "making of video," suitably titled "Herding Cats," notes that at one point a cat managed to get over a barrier and inside a crevice—which meant that they cut a hole in the wall to let the cat out (unharmed). There's something rather natural in the way the cats climb to high spots, with territorial advantage, or find other cats to form a pack, however temporary, or hide, or, as the kittens do, happily explore and play without needing to exert dominance or claim status.
Happy Inside commercial
"Herding Cats: The Making of the Ikea 'Happy Inside' Commercial"