Tall person - loosening, or basically dropping the force down to earth as such short guy is trying to push horizontally but force is going down. Its dynamic not like pushing a stone wall.
NOPE, wrong direction.
i was going to drag this out by giving hints and stuffs like that, but this is a long thread already.
consider a few things first: short person never lost his structure, short person doing the pushing, and (the obvious) short person has center of gravity lower than tall person.
the exercise is a game (also a training scenario) - how to get your center below the other person (internally). the reason the short person kept bending his knee is to get lower and lower (obvious, no?), because every time he pushed the tall person, the short person felt he was pushed from below and floated up, while the whole time the tall person didn't move at all. so, the direction is up, not down (down is too easy considering the height different). if any of you folks got a chance to play with Ikeda sensei, the words of his description is "I pick" *with an accent and a smile*
thing to consider, as long as the short person pushed, he went up, but if he stopped pushing, then nothing happen. btw, this is a very basic scenario. if you know how to do this, then you know how to apply it in kokyu dosa for aikido folks. for judo/jujutsu folks, this is a silver bullet, to be able to float your opponent at will.
to me this is aiki in static mode, to move another person energy in any direction at will.
*just another traveler on the muddy road of aiki*