It's a form of natural unweighted squat that's commonly practiced in Asia as a rest position.

A crucial difference from how many westerners squat is that the weight is carried back on the heels. Westerners tend to squat with weight forward on the toes, which is highly fatiguing.

There's a vintage video on the topic:

https://www.youtube.com/watch?v=y76UbfBr5vo

(This was linked in the article, but it's since gone walkabout).