Students learn joint locks to immobilize their partners, getting further proprioceptive input. Most of the techniques are done in a kneeling position as well as standing. This is taught for the very functional reason that, until recently, kneeling was the way Japanese sat in their homes. They were expected to be able to employ self-defense techniques in whatever position they were likely to spend any length of time. The suwari waza position, halfway between kneeling flat with the feet tucked under and tall kneeling, is an excellent one to develop trunk control and balance.
Students learn to move with their partners and be sensitive to their movements.
They learn interpersonal skills like taking turns. They learn to respond to physical and verbal feedback. Most of these skills are taught to children through games. This sounds pretty demanding, especially for a child who may lack physical and social awareness. But when the skills are broken down, they can provide an enjoyable path to greater awareness.