Politics make a photo iconic. Ansel Adams' photos of Yosemite depict human absence. Of course he was there and married into the family of the shop selling photos of Yosemite to the people staying in hotels in Yosemite. And the indigenous people who called it home had been removed to create what Yosemite became.
Beyond that the claims that photographs make toward objectivity reflect a political stance. Look into Dorothea Lange's photos of the internment.
Photographs become iconic because powerful interests use them to tell audiences what we are supposed to feel and whose view counts. There's an editorial decision to pick Niel Armstrong's picture of Buzz Aldrin versus Nick Ut's Napalm Girl to go alongside Earthrise and the Warsaw Ghetto.
It's worth noting that Nick Ut's photo changed people's behaviors more than any of the photographs in the article. But not in ways that were in the interest of powerful interests.
