Texture
The fish scales pattern uses exactly the same alternating system as the half-drop. The only differences are that the fish scales' modules are usually circular, and they are always overlapped. This overlapping gives the fish scales pattern a greater sense of depth (although it is, admittedly, a very shallow depth) and directionality than its close relative the half-drop. While doing the exercise, notice how the transparent modules create very intricate patterns where they overlap.