Lots of lines.
It is interesting to see how the sail making technology has changed since my days on the water. The most important requirement for the materials used for sail making, is that they should retain their shape, or perhaps change shape in a predictable and intended manner, with changing wind strength and point of sailing. As technology has allowed it, it has become much more common to see larger transparent panels, even whole sails, whereas in my day, most sails only had a relatively small transparent panel through which the crew could view converging boats.
The end result is that the sail reinforcement and batten pockets can make for some interesting abstract images.