I get asked all the time: Why are some vintage snapshots considered art? For me, there is no one right answer. The photo above "Sand Dune, 1962" (now in a private collection) is art because it transcends the purpose for which it was made and as a composition it is surprising, captivating, and unique. Since beauty is in the eye of the beholder, I decided to put this question also to long time and very knowledgeable vernacular photo collectors, Roger Arvid and Robert Jackson.
For Roger, there are two criteria for evaluating if a vernacular photo is art: "1) as an arrangements of objects, when the composition meets certain geometric criteria that may be regarded as beautiful or compelling; 2) in regards to subject when the historical is more than just cognitive, but is superseded by a level of universal empathy that leads the imagination to construct a fictive story that is inclusive of the viewers feelings and emotional attachments as stirred by the elements or people in the photograph."
According to Robert Jackson (whose collection is the subject of the National Gallery's exhibition and publication, The Art of The American Snapshot, 1888-1978,
considering the snapshot as art involves "distancing oneself from the
social aspects of the photo—from not “reading” the photo to divine its
narrative story both personal and within a social milieu, but looking at
it instead with a formalist eye to its composition, aesthetic
sensibility and achievement."