In Berthe Morisot's Summer's Day,why Is One Woman's Dress with Zigzags

In Berthe Morisot's Summer's Day,why is one woman's dress with zigzags while the other is a patchwork of straight strokes?

A) To distinguish the clothing from the water
B) To show one's social superiority to the other
C) To emphasize the distance between them
D) To capture the diverse play of light better