All of my QAYG are viewable on my page QAYG gallery of quilts.
Here's the shortest possible explanation:
Two versions of the narrow connector strip. On the left the narrow strip is on the back, and the doubled strip is on the front and topstitched to cover the butting seams. The version on the right has the narrow strip connecting the two top sections, while the folded strips covers the seams on the back, and is pinned from the front and top stitched, in the ditch or near it.