This is a gimmick to illustrate the TZI-Model. If one of the gactors weights more, the model will be out of balance. It is required to have all factors balanced, and so also the model is balanced. This is based on the theory of Ruth Cohn:

Ruth-Cohn-Institute

Wikipedia

The Model is about 10cm wide and the lower part is to balance the board. Possibly it needs some afterwork with a file or a cutter to improove the balancing. I also printed a larger model with a factor of 1.8 and using filament switching. This added a very nice contrast. If you tip on one side carefully it stays on that side to show the out of balance. With the smaller one it was difficult to reach a stable tipped state. But with the bigger one it worked.