The concept of aura is a beautiful one; as Groys and others have pointed out, it is an aspect of the here and now experience of a particular object, or more properly of the loss of such an experience, and any critical concept that bears on the poverty of the here and now is valuable. But like all concepts it is a trap. The specifics of how and why a picture, for example, is expressive, and what makes it glow, cannot all be subsumed under the aura. The glamor of the commodity may always be there, it may contaminate all our experience of a work, but a great work is not reducible to that. Perhaps the contaminating effect of the concept of aura is a variant of the drive for total power present in all abstract concepts.
I think that the aura withers under the gaze of the professional artist, who is really only concerned with specific effects and how to produce them, and not at all subject to their spell. I like to think of the set designer of a play. On opening night, sitting in the back row, he or she will see only the flaws, but even allowing for normal human anxiety and doubt, what their critical gaze will register is the joins, the mechanics of how the set fits together. They will never be able to surrender to the illusion, as all the audience will do. The same applies to the director and writer for that matter. For the artist there may be another pay off in pleasure at the end of the working process, but that can hardly be the same thing as the unconscious worship of the commodity as fetish. The collector or the consumer may be left with that, but the only adequate viewer of a work of art is another artist, because only the artist is obsessed with technique, with how things are done. Even the most perceptive critic is likely to have a much more theoretical interest in the object. All of that opens up another huge problem, but for now just say that the organization of lines, colors, shapes, spaces, allusions, memories, images, concepts in a work—the particular arrangement of particulars that in a particular case moves our emotions and fascinates our minds—is difficult to achieve, difficult to perceive, and worth something.