The kid looks pretty much like a beginner just starting to learn the moves. From the smile on Ueshiba's face, he does seem to be just having some fun. Hey, he knew he was on-camera! Great photo op.
But he did put the kid's arms in position and walked him through the technique, like someone's grandpa might put his young grandkid on his lap and "walk" him through the motions of using a screwdriver or hammer, holding the child's hand with the tool in it and making the movements. Doesn't look like there's anything "deeper" than that going on.
Nice old film clip showing a different side to the "Old Man."