Did they hire Lanvin's show editor this season? The official show on the YSL website is full of slow-motion and detail shots in time to the music, which enables you to see the details very clearly.
They did indeed, it's Séraphin Ducellier's S75. It says on his website that YSL is yet another brand to be added to the list of the ones Séraphin works with.
You can definitely see the Lanvin-esque touch in this video (in the length as well, as Lanvin videos became shorter ever since they hired S75 too) and I really appreciate the focus on the details. Makes me love the collection even more.