Claiming that images of naked women were central to depicting mythological or biblical stories was a rationale frequently used. Martin van Meytens’ double-sided Kneeling Nun painting (~1731) highlighted an additional cleverness in “hiding” taboo imagery and deflecting personal involvement when viewing overtly erotic imagery. On one side of van Meytens’ painting is the image of a pious nun, hands folded, kneeling, leaning on a railing. On the other side is the bare backside of this same nun. To remove the viewer from the “guilt” of enjoying the earthly pleasure of seeing the nun’s naked bottom, the artist included one additional image. In the top right corner is a lascivious old man who is the voyeur, instead of the viewer of the painting. The lecher then absorbs the guilt; the viewer is free to admire the artist’s brush strokes. (http://beinginstockholm.blogspot.nl/2011/08/swedens-national-museum.html)