What particular features of aesthetic writing can be found in Puig's Kiss of the Spider Woman?
I think that construction of Molina's films through language is a fairly strong example of aesthetic writing. Consider that film is a visual medium and that there is little verbal description evident in a film. Molina, not having access to any visual media, must use his own powers of language to redescribe the emotions included in the medium to someone, Valentin, who has not seen the film and holds nothing but ethical repugnance towards it. In this condition, Molina, and by extension, Puig, demonstrates a strong example of aesthetic writing in how he is able to construct through language that which is visual.
I think that another example of aesthetic writing would be how Puig is able to move both his main characters from opposite polarities to a central point and then diverge them into the opposite of what they were by the end of the work. Molina and Valentin start of opposing one another with the latter being the political revolutionary and the former being of the delicate aesthetic realm. The convergence of both is through their own relationship, one that shows how consciousness in the modern setting requires both the political and the aesthetic in order to find some semblance of happiness. The divergence happens when Molina becomes the revolutionary, for all practical purposes and dies like one, and Valentin succumbs to the aesthetic dream, "short, but one worth living." This is an example of thematic brilliance, but is constructed with an eye towards the aesthetic. Puig recognizes that since both are needed in the thematic structure of the drama, both are needed in its retelling. In this, there is a great example of the power of aesthetic writing.