The waist/heel tapering is part exaggerated by the very strong Cuban heel and part exaggerated by comparing it with a much larger shoe with outside squared inside beveled waist. The left shoe also has seemingly higher arch as well.
Not sure if that's a Cuban heel or just high heel... Very interesting choice indeed.
The small one looks like 1/4 the size of the larger one (with a traditional robust French heel). The heel height looks the same. I wonder if it was a pain for the shoemaker to pull it off.
Beautifully finished though!