Well, this is just Magical! First of all I'm amazed how You made Pinkie. Her face looks so enchanted by the pond and hel nuzzle makes an impression, that she is actually saying "Uuuu! Magic mirror lake!". Than there is absolutely stunning background. I would call this a friendly darkness. It reminds me of some of locations in the game and concept arts of The Elders Scrolls III: Morrowind. At first I thought there is one thing that is missing. Big glowing mushrooms. But on second thought it came to me, that underground, moist caves almost always has big glowing mushrooms in fantasy so it become too common thing. You made a good decision (in my opinion) with making them normal size. All in all I would say that this is one of the best of Your pictures. I have so much respect for those countless hours You spent to learn to do, what You are doing. And You are creating magic!