Unfinished Hand Pieced Double Wedding Ring Quilt on sale Top Circa 1940

Unfinished Hand Sewn Double Wedding Ring Quilt Circa 1940? Expert Needlework. This is an unusual piece in the way it was put together. The last pieces to be added were what traditionally would be a four square, but as a quilter, I'm curious as to why she didn't add them before putting it all together.