The "JO Trick"
There is a story, I believe in one of Shioda's books, where he describes a pre-war Osensei teaching at a military academy, and challenged, stretches his arm with just his pinky resting on the edge of a table and has a number of men lie across his extended arm. Either a fantasy or it happened.
More directly, there is a wonderful photograph I:ve only seen once - with Osensei standing with his arm outstretched, with an obi or cloth looped around his extended arm and one or two guys hauling at the rope - Osensei unmoved. That picture looks very believable.
I believe that the Jo-trick is an *extension* of that level of power, coupled with "I cannot move my teacher" - BUT, Terry Dobson tells the story of never believing this trick, and jumping up and slamming into the guys pushing and simply bouncing off.
So what do I think? I truly think Ueshiba, due to his far greater level of training, has abilities beyond such "tricksters" as Tohei, for example. (Oh, please, don"t get upset. I put " " around the word). So either he could do it, just as it appears, or, as is more probable to me, he had a level of skills and power that were, in this demonstration, enhanced by the support of his students.