4 years of breaking free

it's barely depicting the vulva (the external hole is visible in ONE panel, from a distance, and otherwise you are only seeing the internal organs), and its clearly health information. calling it a "cartoon of a vagina" is kind of obscuring the specific context of it being a very tame medical diagram showing how to do something that many people do every month starting from middle school.

tumblr's definition of "mature":

What is considered Mature Content? Content not suitable for all ages, including text, images, audio, and videos containing nudity, sexual themes, strong language, or mature subject matter is considered mature. Posts that contain mature content must have a Content Label applied, and it is your responsibility to label your content appropriately. [...] What counts as sexually explicit? Visual depictions of sexually explicit acts or content with an overt focus on genitalia are not allowed on Tumblr. This includes sexual intercourse, masturbation, sexual interactions with toys, and content involving bodily fluids. We also don’t allow content where aroused genitalia is visible or the primary focus, even if partially covered or beneath clothing.

tumblr's official age requirement is 13+ and plenty of 13 year olds use tampons. so there's no reason to me that image isn't suitable for all ages (13 year olds should not be protected from basic sex ed), it isn't sexually explicit, it doesn't even have an "overt focus on genitalia" despite being about genitalia, and the actual post is also just about nonsexually caring for a neovagina. "mature" is very clearly a label meant for erotic content, not non-erotic sexual education.