Thank you kindly for your nice and detailed comment.It's motivating to see someone looking at one of my pictures for a longer time to notice the little details I tend to sneak in. So, once again, thank you for that and that you took the time to write it all down.As for the roots... well to be honest it struck me while doing the roots, that the library will grow larger over time. I first noticed during my picture of zecoras hut, that this houses which were built into the trees look as if they were grown out of it. They all look very organic and the tree looks still healthy. So (in my imagination) the possibility exists that this is the cause of some magical or alchemistic influence (Zecora, Twilight) and so, if another room is needed or if the roots should grow in a certain way, the Ponies know ways of doing so. But thats just my train of thought that occured to me while doing the picture.