We had a seminar about 2/3 years ago. The visiting shihan explained to us something about "aura", and that it can be developed. Some people have "thin" layers while others have "thick" ones, sort of like an extension of "ki". Naruto calls it chakra
He said these things can be worked on. Similar to punching, before it reaches the target it's already damaged (stuff like that). It's the same effect when you are riding a motorcyle and then all of sudden a truck overtakes you, then you have a sidewind sort of.
He asked me to punch him in the chest and not withdraw my hand after the punch, he evaded the punch and started to "slowly" approach me, as he is getting nearer I can feel I am starting to move, tilting so to speak, and..... he gets nearer and nearer until his "gi" touches mine and I was completely unbalanced and down I went.
Did I feel power? Not really, it was something else. There could be another explanation but I felt I was being intimidated, something psychological happenned. I was afraid of him. I respected him, and I believed in him, etc., etc.. Put all these factors into consideration and then add the "aura" thingy and there you go.
Well about the video, I think uke is not resisting and that uke is well focused on absorbing nage/shite energy, or another way to put it is that nage's aura/energy is just thick enough for uke.
That's just the way I see it and I am just a newbie to aikido.