A great wedding photojournalist is a great story teller, using photos instead of words.  The photos should contain elements that help define the moment so no explanation is needed by the viewer.  The photojournalist can blend into the background and become a fly on the wall, allowing all the candid moments to unfold.  They should be vigilant too since so many things happen on the wedding day.  You don’t want to miss any of the action, it could be the peak moment so stay on your toes.