WE NOW DO COOKERY LESSONS! Just kidding, I just found some polyrhythms around my kitchen and decided to share them :) . Polyrhythms mix different beat patterns to create interesting grooves.
The cabbage is in 4/4 and it sounds like the other beats are in x/4 for the most part with the same tempo. Wouldn't that make them polymeters? Or am I confused? (probably)
So I'm thinking of those other parts as being half notes (two per bar), triplet half notes (three per bar), quarter notes (four per bar), quintuplet notes (5 per bar) etc. all relating to the underlying 4/4 meter. A polymeter would have different downbeats going in and out of sync - essentially two (or more) competing meters running independently. This article is good on the difference: music.stackexchange.com/questions/10488/polymeter-vs-polyrhythm