It's a nursing pillow. My brand of choice is the Boppy but there are a ton out there (none of which I've tried...and trust me I've paid for my own pillows...so this isn't a "review").
I've never had a baby without having one of these handy. It's great support for the baby and makes it easy for a weary, labor worn mama to nurse her baby. Not only that...it's great support for the baby while you just stare at how precious they are!
Case in point...Ceili Rain on her pillow!
Last year, I lucked out and found a "naked" pillow at consignment and it was in great shape. There are slip covers that can be purchased at various stores. And I found this cute little slipcover for the little princess's birth. Now, seeing that reminds me I need to look for a little bit of a boyish one for Bry!