>>300386030
That clip is a lie. That's just custom maid which has no tracked object support. They've just put the doll in the same position as the model in game and it won't move it at all.

The concept exists in:
https://www.dlsite.com/maniax/circle/profile/=/maker_id/RG35356.html
https://www.dlsite.com/maniax/work/=/product_id/RJ188839.html

But it barely works. It's just triggering animation states with low accuracy.