Overall, it is quite bright and lacks form, as it seems flat. Edge control is possibly it, but if you refer back to your previous dragon study, you see a lot more shapes going on. I think for the kind of style that you're going for, you'll have to either invent or force certain shapes on characters. You're very keen on expressing the shapes around the eyes, wrinkles, the brows, the cheekbones, forehead and so on. And this is great, because it shows that you understand the form and that you like playing with it. Where you struggle though, is places of low detail. In the last thing you did, the dragon in the middle had more edges than the last one. Alexstrasza's jaw had a few bright planes, but those were removed in the last one. That is why it has more of a cel-shaded look, for it really lacks the values and texture/plane detail that you usually put out. Either way, the dragon in the middle definitely has more shapes, with bright oranges and dark reds, which are all killed in the last one.
This means you were probably not satisfied with the way form was presented, and you decided to simply smooth them out/remove that. I probably don't have to say this, but if you indeed were not satisfied, then it means you lacked knowledge about dragons (even though they aren't real), reptilian heads and the planes on them. Which means, you need more references! Or to study that kind of stuff more I guess 
Either way, its great.
And as a last note, Laurel is quite interesting, as she kind of gave birth to this modern blizzard look. Now, she made many paintings but I'll refer to this one for simple reasons (it's old, quite close to when this style went complex).
Now, picturing blizzard art in our minds, we always imagine over exaggerated forms and sharp edges with heavily saturated darks. But, this stuff is on so much crack that you really can't imagine it imo. The style is hyper stylized, and you really have to keep in mind how intensely they've crafted this stuff. They really do push it to the point of where it almost looks wrong, as far as they can go. Now, this hogger painting is really nice I think. It's from 2011 and really shows the basics of this style, how hard the edges usually are, which shapes are ever shown/formed out, where the focus is and such.
Sorry for the ramble, keep being awesome! Looking forward to more Laurel studies 
