I really like the block but it's not the SnW that was created by Bethany Reynolds. It is the kaleidoscopic image I think of when I hear or read that term.
http://www.bethanyreynolds.com/
"Stack-n-Whack is an easy way to create quilt blocks with unique kaleidoscope designs. These designs require a set of identical pieces cut from a print fabric. Rather than finding and cutting each piece individually, a quilter can cut and layer a number of large, identical print rectangles to make a stack."