Girls with chest size far below the breast size of the attire, so that the difference is noticeable. The attire in question are mostly bras or bunnysuits, although bikinis and other skintight garments (spandex and the likes) usually does not qualify since they are designed to cling to the skin instead of having a definite cup shape & size. Also, the attire in question must be more or less properly worn, as to emphasize the size dissonance.