Late afternoon on a sunny day is the best time to look for interesting shadows. Fences, gates and railings are promising candidates. Although this photo isolates the shadows from their source, I think you can tell that this particular railing is modern in design. The steps distort the rail posts into slightly curved stripes. Those slightly wonky lines will look comfortingly familiar to any quilter who works in an improvisational manner. Quick---get out the rotary cutter but don't bother with the ruler.