While still finishing a loop in the z-order, seemingly. Method depicted on the original image showed how every tile can be the same except one for the final stitching on top. Although that's quite a neat solution to work with one kind of tile only, that means at the end you need duplicating -or better, cloning-, and use clipping on the duplicant. Method depicted here needs neither duplicating nor clipping. The downside is that you need three individual tile shapes.
overlapping object free icon was designed by Lazur URH for icons Png and presented to its users.
Lazur URH
11/17/2017