It is quilted with unmarked, improv straight line quilting with a walking foot. Just following the X seams in the central portion of the pillow using the presser foot edge as a spacing guide. Unlike concentric circle quilting, I began the concentric triangle from the outside (I started sewing beside the X seam) and worked my way into the middle of each pieced quadrant.
The white border is stitched with white thread in improv zigzags that end up looking like wonky triangles.
...and of course I love a longer stitch length for straight line quilting. I set my Pfaff and Juki to 4.0. The binding is machine sewn to the back via a stitch in the ditch along the front seam.