Maybe I'm lacking art appreciation skills, but all I can think about is how bad these "paintings" must smell... GROSS!!
I don't even like to see/touch/smell that stuff when it's on its way from my body to the toilet/garbage can (via tampon or pad)... get it away from me as quickly as possible. I certainly don't want to see someone else's uterus lining exhibited on a canvas.
But hey, each to her own, I guess. (Damn hippie.)