I found this anime through the 'Thinking and Drawing - Nihon no Shinseiki Art Animation' and therefore, already expected something artsy from the show, but this short anime was frankly quite good.
The art, animation and sound were superb, very well arranged together and made the 7 minutes very entertaining. The way the music blended in was specially well done.
I cannot recommend this to every one though, as this is very artsy and may not be that amusing compared to many other anime out there.
Now to the personal interpretation corner:
First let me note that the Japanese name "部屋/形態" means literally "Room/Morph" which I interpreted as "Morphing room"
Through the short, it felt like the paint on the wall was not only a reflection of the window, but represented how a story gets told. The development of the story told by the projections on the walls were tainted when passed though the windows and therefore acquired unique traits, represented by the shadow of the wooden part, interring the projections of the story being told. The sudden appearance of colors may as well represent how we perceive memories as good, bad, pleasant and unpleasant.
Interpreting the show was more than half the fun, Id' recommend you do it too! :)