For the children, this apparatus provided the opportunity for them to move the sand from the sensory table out of the sensory table to a tub set next to the end of the table. That was important because---as stated in axiom #1 on the right---children need transport what is in the table out of the table.
Besides all the action up top, there was also a commensurate amount of action on the bottom. Interestingly, the children at the bottom could not see when someone poured something down the tube because the box itself obstructed their view. As a consequence, they were often surprised when something shot out of the tube.
Over the course of two weeks, the children had two separate experiences using the same apparatus. Corn streaming down the tubes was much different than sand streaming down the tubes. The corn had a different smell; it was lighter, faster and noisier; and it was bouncier than the sand. In essence, the children had an opportunity to compare the characteristics of two different mediums through the same apparatus.
That sound likes science.