This technique looks confusing, but is not difficult to sew. These alternating pleats are just created by marking pleats at the top, and the bottom. The pleats at the bottom should be marked directly in between the marked top pleats. When you sew the pleats, it looks like the fabric is folded in on itself and intertwined together.
JUDY MARTIN : Rough couching, over raveled weft threads, un-separated floss, and narrow strips of denim. It evokes Starry Night. "The threads and fabrics are familiar things used in an unfamiliar way. What is usually used to make a neat seam or a mended pocket, is used here in a messy and raveled manner." Read her post and enjoy the detail photos.