I wouldn't want a painting of menstruation on my wall, but I have seen in the city art gallery of modern art a very large painting of a naked and obese woman who was obviously of very, very low intelligence lying on a scruffy sofa with her legs apart, and a lecherous expression on her vacant face, in a parody of paintings like Manet's famous one of the beautiful courtesan Olympia reclining naked, waiting for a client, or of Titian's Venus of Urbino.
The reaction of the group being shown this painting on a tour of the gallery was one of disgust, and some said that it shouldn't be on show to the public. Yet when shown Olympia, they had accepted it as "Art".
The tour guide then explained the artist's motives in creating it. Both women are in approximately the same pose - but one elegantly, the other inelegantly. One is young and beautiful, the other older and ugly. One can make intelligent conversation, the other would be hard pushed to make any conversation at all. Yet they both portray women whose raison d'etre is the same - as sexual objects for men to lecher over and use. Naked women are Art with a capital A if the reason they are naked is disguised, but not if the disguise is dropped and the sordid reality revealed.
I wouldn't want this on my wall either, but in a public gallery, accompanied by text from the artist to interpret it, it is a reminder that admiring an "artistic" sexual nude but not a "disgusting" realistically sexual one is a form of cultural hypocrisy.
In the years before Manet exhibited Olympia, women in public paintings were usually shown fully dressed or coyly draped in diaphanous draperies. Olympia received reviews very similar to the comments on here about depicting menstrual blood. Nowadays nudes like Olympia are part of the art "establishment". The painting I saw was a progression to show a sexual nude "warts and all"
As a parallel, any mention of menstruation, particularly in mixed company, used to be taboo, but no longer is it mentioned only in euphemisms in private. I have not seen the picture referred to, but I imagine the artist probably means it in much the same way - as depicting female physical reality "warts and all"