The fact that photographies of artworks, for example for exibition or collection catalogues, are oftentimes pictured without their frames, shows their secondary importance to the contemporary art beholder. The role of the picture frame was subject to a change in exibition practices and lost it's function as a representative part of the painting. But the history of art is closely entagled with the history of the picture frame, since institutions and collectors throughout time have always seeked an aesthetic unity between the artwork and it's frame. But with every new Owner a new taste and therefore a new frame was introduced to the painting, one that would preferably unify the collection or establish a relation to a specific period in time or just to accomodate the painting to it's spacial or institutional surrounding.
In regards of this volatile characterization of the frame, which marked it as a replacable component of the artwork, the frame lost it's aesthetic affiliation to the painting.