Photography's Expanded Field

I really struggled comprehending the diction and terms in this article which detracted from my understanding of the overall message.  From what I understood Barker is explaining the postmodernist movement in photography.  The defining characteristic of photographs during this movement is that they are part of a longer or larger story or scene.  Photographs represent a single still in a story that let the viewer construct a narrative.  

I thought it was interesting that Barker describes this as a characteristic of postmodernism because this did not feel like a new observation.  Many of the photographs we have looked at in class seem to be just a fraction of a story.  For example, Cindy Sherman's photographs where she purposely positions herself to look as though she is in a movie.  She even titles her photographs film stills.  Also, I felt that straight and documentary photography was, in a way, attempting to create a narrative of rural American life.  The photographs taken by Lange and Evans seem to tell stories about the lives of the people they are photographing.  Especially Evan's pictures of the tenant farmers families.  

Postmodernism might have been the emergence of photographers taking pictures with the intent of trying to allude to a longer story, but I feel like all along photographers have been telling stories with their pictures.  Therefore I felt confused by Barker's message for two reasons: first because his writing was unclear to an inexperienced photographer and second because I disagree with his argument.