Yes, it's the knife edge setting, it looks amazing in pictures, I'll look at it in person tomorrow.
If you got the knife edge setting it looks like a Tiffany ring, in fact I think it's nicer than a Tiffany ring, but passing it off in a Tiffany box is a really dumb thing to do, give her the ring in another box (the Brian Gavin ones have always been fine) and then give her the other boxes, if she wants to pass it off as real Tiffany to her friends and family in photos that's her choice. I also think that's another dumb thing to do. She has a ring and a diamond better in quality that Tiffany, that's all anyone needs to know.