I think as Serge isn't here , what he may have been suggesting is two fold..
Firstly that the use of photoshop techniques detract from the artist value of the peice in the same manner that a poster of an oil painting does not show the depth and structure of the brush strokes.
Secondly art should stimulate some other deeper more "felt" reaction besides that of the visual of the subjects.
Anbd on this I kinda agree.
Its a nice touched up picture of a fat beloved cat....but is it art?
To me it is a picture of a cat sleeping on a sofa.
To you it is art