This tip from Ruth Wyeth Spears and the 1920s focuses on accent pleats that fan out in sun rays. I particularly find the side godet interesting, and the use of the pleated fans at the hemlines of both the godet and the "scarf collar". Ruth's explanation and drawings (she drew all her own illustrations) are perfectly clear, as always.
Note the title in this article. Rue de la Paix was (and is) the fashionable shopping street in the center of Paris. Fifth Avenue in New York, of course, is lined with prestigious boutiques and flagship stores and is consistently
ranked among the most expensive shopping streets in the world. So "sun ray plaitings" was a current trend that was evident in the leading fashion houses and shops of the day.