I don't think it was irresponsible. If someone were to see it and say "ooh, I should make my slave do that," without asking first about whether the noose was functional, how much experience the model had wearing the boots, etc., that person really should not be dominating anyone IMO.

I also think it's a beautiful picture. As a dancer myself, I like the way it alludes to relationship between the intense pursuit of beauty found in the ballet world with that found in the fetish subculture. And the model is truly beautiful, of course. She has wonderful curves.