Pretty Midi Dresses.
All clothing will certainly fit tightly around a good animated woman's 15 " waist, even if it's decreased or empire-line. Men as well, will have an apparent thin waist even in jackets which wouldn't show that inside real life. Of course , the most common type of this is spandex outfits, that nowadays wrap around each and every curve and muscle (especially prominent since the late 1980s) but as the picture shows, any kind of piece of clothing can cover around better than it should when the artist so chose, whether it is an overcoat or the bodice of a Pimped-Out Dress.
One more, particularly where superhero comics are concerned, is that artists tend to be trained to draw human numbers. It is faster and simpler to add colors that suggest spandex clothing than to really draw the folds along with wrinkles that come with wearing practical clothing. In other words, most of the time (and this goes for male figures as well as female), what if you're seeing are nudes together with strategic coloring.