The short answer to that question is everyone. Back in the fifties women wore girdles to hide any bulges and pull in the waist. Thankfully, women of today do not subject themselves to that kind of torture, but there are a range of body shapers available which can flatten the stomach, narrow the waist and even augment the size of ones bottom. Amazing!
Wiggle dresses might be figure forming, but the various designs can be worn to flatter a range of body shapes and sizes. For example, the wrap over type wiggle dress can accentuate curves, but because of some of the gathering at the front it can also hide small bulges around the stomach area.
Women with a large waist can wear high waisted wiggle dresses to raise the waistline to a narrower spot, such as that beneath the bust, giving the appearance of a smaller waist.
The wiggle dress accentuates any curves that a woman may have, so those with a boyish figure will find that the cut of the dress exaggerates whatever shape they may have, giving the impression of curves.
Women with an hour glass shape will find that the wiggle dress enhances their small waist, and is just as flattering for the curvier woman than it is for those women with a boyish figure.
Because the wiggle dress is such a classic design and isn't too revealing, it can be worn by a women of all ages. The wiggle dress is truly a dress for any woman, any shape, any size and any age.