If it really, really bothers you, probably need to take the binding off and reapply it. When doing so, tug on the binding just a bit to snug it into the quilt. That's my guess on what has happened and how I'd fix it. Unless this quilt is to become a wall hanging where the ripple can be noticed, I wouldn't be concerned about it though. It's a darling quilt--good job of creating this giraffe family--plus tails!