Seriously. This book is genius. Really helpful for me as I started learning Crossfit while doing lots of Yoga. Gradually helping me reduce mobility limitations and helping open-up yoga poses (asana) that I would have had to wait for much longer to achieve.
Basically it's a series of pictures showing two people doing some partner yoga with a paragraph of 'poetic' text linking the various pages. The comment 'the art of partner yoga' is exactly right. It's an art book with no useful commentary on the asana themselves. So, for me, not what I wanted at all. If you want some nice pictures and a little poetry perhaps.