So I did a little digging to see if he had done any more fairy tale art that might be either subversive, or what significance there might be in his taming down his own fairy tale illustrations. In general he embraced "perverse and grotesque erotica," you can read more/see some of his famous images over on Wikipedia. However, it turns out that he wrote his own version of the Cinderella story to accompany his illustration, and although the image itself may seem innocent enough, the story is more along the lines of the "dark/twisted" fairy tale interpretations that are popular today.
Beardsley's own interpretation of the classic Cinderella story, appearing in The Yellow Book of July 1894, clearly personifies the powerful role that fashion has within a society. Beardsley changes the ending of the story to turn happy children's fairytale into a murderous mess of fashion and jealousy. Beardsley's version thus addresses the reader,
You must have heard of the Princess C. with her slim feet and shining slippers. She was beloved by the prince who married her but she died soon afterwards poisoned according to Dr. Gerschovius by her elder sister Arabella, with powdered glass. It was ground I suspect from those very slippers she danced in at the famous ball, for the slippers of Cinderella have never been found since. [Quoted Heyd 123]
I can't find the actual full text for the story online, does anyone know where it can be found? On the one hand, many of us are getting a little tired of the whole "let's make fairy tales DARK and VIOLENT and for ADULTS!" movement, but Beardsley's ending was at least original and not jumping on a trend; and there's a sense of realism especially when contrasted with Perrault's Cinderella completely forgiving her stepsisters with no apparent consequences for either their behavior or the tensions in their relationship.
Beardsley was specifically criticizing the world of high fashion, and his works suggest that he "believed that Victorian fashion was a dangerous and powerful means to control and constrict women." (also from victorianweb.org)