The substantial transparency of an anasculpture induces to interact with it by placing an object, a part of the body or the entire body, between the active plate and the background, depending upon the width of the gap. The effect of “trompe l'oeil” suddenly vanishes and the observer, having experienced an enigmatic feeling: is he in front of a painting? of a three dimensional object?,  is again required to cope  with a neither-nor reality that he did not expect.