I agree that the dragon was extremely cool. But in the video, it seemed to me that the "magic" was exposed when it breathed fire (the light of the flame seemed to reveal the glider for a split-second). Perhaps this was even more obvious in person and they decided that it wouldn't be convincing. Also, depending on whether it's a very dark night with little moon or a full moon could make a huge difference in what is and isn't visible. Still, it would be amazing if they brought it out now and then when conditions were right.