This is probably a bit too old to reply to here, but I want to suggest (in case others see this) that the reason your animation doesn't resemble wolfenoctis' animation even with your edit is simply because the silhouette doesn't change enough during the animation.
To check this, get his animation and black it out to see the silhouette (i.e. black body white background) and do the same with yours. You should notice that his back legs appear to get wider as the butt comes up toward the camera, which changes the shape of the silhouette of the hips and feet creating more CHANGE in the silhouette of the dragon. Additionally, the upward movement of the glide in his edit of the wings changes the silhouette of the wings too by changing their SHAPE a lot more. The biggest issue with your edit mainly is that there isn't enough change in overall shape of the wings to make it seem as fluid and flexible as the type of creature in which you're trying to represent.
Flexible creatures, in general, have lots of arcs that change when they move -- these arcs rarely stay the same, especially on longer appendages, and even more-so on long/lanky snake-like creatures. You need arcs that overlap lines as well as opposing arcs to overlap. Get this down, and you've got it. That is the sort of thing that can help you change the silhouette most easily.