this is a really important factor that will contribute to how one's image will/should be read. (besides the usual technical aspects, which a good 90% of the images here are usually being commented)
other than walter benjamin's writings, (especially the essay on the age of mechnical reproduction) one should be really take on the theory and study of semiotics which will in turn allows you to see images in different lights. Sub-genres in semiotics will include feminisim (eg. cindy sherman), modernism (rodchenko), post-modernism (vannessa beecroft), appropriation (richard prince) etc.
im from a fine arts background, majoring in photography so i would really love to contribute to this topic if there are enough people involved and discuss about it in-depth. every image tells a story, even if its just a picture of a blank wall; it depends how much you read into it.