Each provides something new that the brain can assimilate into its prior constructions, thus enriching and extending those constructions. At first the figure is balanced on its nose so that it stands straight up, then on its nose so that it balances horizontally. Children are challenged to balance it at some of the positions in-between. As the figure is balanced and rebalanced, prior knowledge learned about balancing is reinforced while each new challenge adds a slightly different dimension that the brain incorporates into its prior systems. In FOSS, we call such subsequent experiences rehearsals.
Rehearsals are different from practice.
Practice is when someone does the same thing over and over again to improve a performance. Practice has little transferability. Rehearsal is when someone does something again in a similar but not identical way so that what was learned is reinforced while something new is added. New additions increase the likelihood that the knowledge being learned is not learned as something that is task specific. Non-task specific experiences increase the likelihood that the knowledge will be transferable and useful to the individual in a variety of ways.