Walter Benjamin in a famous essay, "The Work of Art in the Age of
Mechanical Reproduction," claimed that what was lost in a work of art
when it was reproduced was its "aura," a uniqueness that gave
it its mysterious power. But he was also thinking of photographs and wondering
how we respond to them, though he believed they don't have the aura that
a traditional work of art supposedly has.
Roland Barthes, from Camera Lucida: Reflections on Photography [trans. Richard Howard (New York: Hill and Wang, 1981], provides a Proustian answer to Benjamin: photographs do have an aura, the aura of lost time and lost memories. I would add that this aura is sharply increased when the gaze of those who "knew" the person or scene in the photo seems lost.
"A photograph's punctum is that accident [of photographic detail] which pricks me (but also bruises me, is poignant to me), ...for punctum is also: sting, speck, cut, little hole---and also a caste of the dice" (27; slightly rearranged).
"I now know that there exists another punctum (another 'stigmatum') than the 'detail.' This new punctum, which is no longer of form but of intensity, is Time, the lacerating emphasis of the noeme ('that-has-been'), its pure representation" (96).
"But more insidious, more penetrating than likeness: the Photograph sometimes makes appear what we never see in a real face (or in a face reflected in a mirror): a genetic feature, the fragment of oneself or of a relative which comes from some ancestor" (103).*
*[my own thoughts:] Or a fragment of oneself, that comes from saying: "I could have been in that pose, looked like that, done that; that reminds me of so-and-so, or of when I...." This can easily happen when one is viewing photos of those (like these) not from one's "own" family or past. Perhaps it can happen even more powerfully then, when we don't have a readily remembered family story to use to influence how we see and interpret the photograph. Barthes focuses mostly on his own family's photos, or on photos by professional photographs like Sander, Nadar, or Van Der Zee that would now be in musuems or photography books---photos that have not (yet?) had their community of memory severed; or, rather, if it's been severed it's been rewoven in a strong new way.