In the photo of the dress, you might have a hard time telling that the top half of the dress is the "lace" part, and is a stretchy knit fabric, while the bottom half is polyester and not stretchy at all.
fyi: 36c (34d), short waist, broad shoulders/back, usually a 10/12 in a fitted top/dress
the navy lace of the top, as i said, is knit. therefore it was too stretchy, and the straps actually were already too long. it was so loose, that i needed the smaller size in the top half of the dress (10).