But this argument is a old as the hills.
As far as I can judge, whether a work of art is just that or pornography depends on how good the artist who drew, sculpted, painted the subject was. Or for that matter wrote the book or poem.
AND on whether the main purpose of the work has been judged to be only to arouse or satisfy lust in the viewer (reader) or serves some other more aestetic purpose.
If the purpose was to shock, and only to shock then painting a woman with her legs open, displaying her genitalia, or with menstrual blood dripping down her legs seems very Old Hat to me - yes, it caused a sensation in the 1970s, as did pictures of naked men with erections, but honestly, can anyone be shocked today?
Disgusted, perhaps, or soberly feel that the work demeans both the model and all others of the same sex. But again this must depend on the quality and purpose of the work.
In a textbook for medical students, student nurses or midwives or teenage schoolchildren, it might well be acceptable, but not if hanging on the wall of a tea-room.