Note how the side seams are sewn for this 1920s negligee (which, I mean really, it's a frock, is it not?). The body silhouette was pretty straight in the 1920s, and the result is flapper fabulous. :)
Now look at this lovely caftan from the 1970s and Simplicity, and look at the pattern back:
Look familiar? As in the 1920s pattern, the fabric is folded, the neckline cut on the fold, and seams sewn to follow the body silhouette. But since it is the 1970s, the body silhouette has curves, specifically curves that form a lovely contoured A-line. :) Gorgeous.
Hmmm. And I just noticed - both models are posing with a hand to the side of the head, and jewelry, including a bracelet.... :)