Sontag has an interest in the everyday photograph as Surrealist, as a kind of "found object" (see quote on 52)
"Surrealism lies at the heart of the photographic enterprise ... [It] has always courted accidents, welcomed the uninvited ... What could be more surreal than an object which virtually produces itself, and with a minimum of effort?"
Rosalind Krauss has also written an essay on the Surrealists and photography (but direct influence from Sontag is questionable: Davey, trying to answer this question, looks at the footnotes in Krauss to see if Sontag appears there (no))