I don't know about it being on the glass or lens because if you look at the bottom of the screen, it appears to take a few steps(?) and then when it takes off, whatever is right below moves as though it were standing on it and it uses whatever it is standing on for momentum as it pushes off and takes flight. Sorry, I'm not sure if I explained that properly.
At the beginning of the clip it flies in from the upper left and appears to land on the camera.......and this was repeated several times. The motions do appear to be "standing"......but I also see what appears to be a fly cleaning his wings.