It was the corset again, that changed the shape of fashion

1850’s corsets had been waist cinching and because of the improving steel boning, metal grommets, and metal busks, had by that time become restrictive and shaped and formed the body.

(Photo: 1851 fashion ideal sketch and a real 1851 corset.  Waist cinching, it did not constrict hips or force the breasts into shape, and it was still “ok” to have a somewhat “vase” shape on top, meaning the breasts were just sitting on top of the corset and not formed or shaped)