This image is not obscene, but I suspect that more people will be disturbed by it than by a photo or painting of a nursing mother, whether or not her aureolae are visible:
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I was thinking about the arguments about default icons and obscenity, and realized that most images of naked breasts are either of breastfeeding or intended as explicitly sexual (and yes, some are both).
There are images of naked or partially naked women that are neither, but focusing specifically on a naked breast makes it difficult to get away from that. Especially at 100×100 pixels, which often means cropping the image to omit the woman's face and most of the rest of her body.
This icon wouldn't violate the Terms of Service for a default, not because breasts aren't obscene; not because it's glorious and defiant; but because it's of a breast cancer survivor, and the ToS are focused on nipples, not tattoos or scars. [It's not my default; for the moment, the purple trilobite keeps that status.]

I was thinking about the arguments about default icons and obscenity, and realized that most images of naked breasts are either of breastfeeding or intended as explicitly sexual (and yes, some are both).
There are images of naked or partially naked women that are neither, but focusing specifically on a naked breast makes it difficult to get away from that. Especially at 100×100 pixels, which often means cropping the image to omit the woman's face and most of the rest of her body.
This icon wouldn't violate the Terms of Service for a default, not because breasts aren't obscene; not because it's glorious and defiant; but because it's of a breast cancer survivor, and the ToS are focused on nipples, not tattoos or scars. [It's not my default; for the moment, the purple trilobite keeps that status.]