The voronoi is just used to map the x,y coordinates to tiles that then map to images. Doesn't say how the images were selected and the finger coordinates mapped in the first place to generate that map.
[0] https://en.wikipedia.org/wiki/Deep_learning#Deep_learning_re...
"A magician I know talks about the three kinds of magic: sleight of hand, mechanical, and mathematical. The first requires a lot of skill and practice (e.g., palming coins, manipulating cards). The second requires a lot of preparation and engineering (e.g., sawing a person in half, floating person illusions). The third relies on the nature of reality (e.g., dividing sets of cards in a known pattern that forces a result, or manipulating numbers that force an unexpected result)."