It sounds more complicated than it is.
It’s just math.
This is a very pure example of rhythmic subdivision: a demonstration of percussion instruments used in Japanese Kabuki theater.
This piece is a good example of subdivision.
It starts out with long, slow notes, then with each variation, the rhythm is subdivided into smaller note values. Note that the texture is polyphonic.
You will also recognize rhythmic subdivisions in the variations Mozart wrote on the children’s song “Ah, vous dirais-je, maman” (a tune you will know by another name). What is the texture of this piece?