Think of the ever popular 1929 Evening Gown with Handkerchief Hem as origami in dressmaking.
When sewing this design together, you will 'flip' the Lower Back and Side piece after joining it with the Front piece at notch '4'. This ensures the piece will fold and drape to create sharp points in the hem as well as bring notch '6' in the upper edge of the Lower Back and Side piece to align with that on the Girdle. Hopefully this paper mock-up demonstrates the point (pun intended):
Here is a creative twist put on this design as sewn by a customer for Halloween: