This is an absolutely beautiful drawing!
Firstly the expression and motion that is held within the drawing is just phenomenal, the added curls in the tail give it that mystical flare.
The lighting is beautiful, with the implications of many meanings, and despite it's simplicity it is very effective. The shading is soft on the dragon and very realistic, making it fit with the background perfectly. And I cannot resist the tail of the glowing eye, that's utterly fantastical. Love it.
The background is also perfectly suited for the impact of the image, the greying snow doesn't compete with the lovely blue tones of the subject. The black frames at either side of the image also brings the viewer's focus in, which is a brilliant use of something so simple.
Overall, this is a stunning image!