You actually attach it to the handle of the carseat, put the bottle in and position it to baby. I also saw (at the same place) teddy bear bottle holders, they look like they're to help baby learn to hold the bottle. Baby can hold the bears arms, in turn holding the bottle up themselves.
Re: Anyone seen this
I have to smile and think that you all have never had to babies screaming for food at the same time. But would I use that, no.
I actually saw one of these at Baby Depot (Burlington Coat Factory), your post made me think of it -
https://www.amazon.com/Bottle-Feeding-Bebe-Sling-LLC/dp/accessories/B003Z6AOAW
You actually attach it to the handle of the carseat, put the bottle in and position it to baby. I also saw (at the same place) teddy bear bottle holders, they look like they're to help baby learn to hold the bottle. Baby can hold the bears arms, in turn holding the bottle up themselves.