Prior USAF crew chief here. My opinion that C-17 video was taken with only the APU running. No way you could hear the Afghan kids over the jet engines if all 4 were running. I stood out front parking theses big boys over and over with ear plugs and my davy Clark’s headsets on because of the noise.
It was being towed or pulled with only the apu running, my 2 cents after watching the video 3x.
Also look closely at the nose landing gear.
You can see something going on there.