Bargello Inspiration

I did not make this quilt! I bought it in the Finger Lakes, from Weaver View Farms Amish Country Store. They have a wide and amazing selection of quilts, all hand quilted. The tag is still on it, since I've only used it to measure and copy to make my own Bargello. I could not figure out how a pattern with all right angles and straight lines in the piecing could give this wavy quilted effect. After making two of my own Bargellos, I get it.