Yes, it's live compositing. I often use Kinect in combo with video layers (events, museums etc.), but since I also love working with Spine I had to make this. In this case I am sitting on a bar chair with my feet on an old desktop PC. Note that the sideways tracking with Kinect is always a little tricky. The composite could use a little bit better masking and maybe some shadowing. And of course I could use Kinect gesture recognition to trigger the "roar" animation or other fun scenarios.