Excerpt from this article:
Flip to your emoji keyboard and scroll until you reach the clothing options. You’ll notice five shoe emoji; a brown “man’s shoe,” a gender-neutral trainer or sneaker, and three high-heeled women’s shoes. Hutchinson says this absence of a flat women’s shoe emoji is problematic.
“The fact that women cannot opt in to have a female shoe without a heel is deeply problematic as the vast majority of women simply do not wear heels in their daily lives,” says Hutchinson.
“The implicit expectation, albeit a virtual one, that women would and/or should wear high heeled shoes (be it a stiletto, a mule, or a boot) is simply absurd,” she continues. Hutchinson notes that her campaign is far from a “stiletto boycott,” but instead an effort to give “women who prefer flats” an icon they can identify.