Celestia looks so small here. Not just because of the comparative size, but also because of the proportions - she almost looks teenaged. That's not a bad thing, however.

Love the painterly take on the curtains and the reflection on the floor and the columns. The vines are okay, actually, I really like how they turned out, very Canterlot-y, if Rarity's taste is to be believed. Great work with the tones of orange on the roof outside, too! All in all, some pretty good and solid painterly work here, though the somewhat thick sun-supporting spire on the smaller tower in the back makes it look a bit rough to me, somehow. But it's not a big detail.