We then assume that all photos are real in a way that other art is not.
I think we find it difficult to escape immediately responding to a photograph as-if it were a frozen reflection.
Sometimes as-with a distorting mirror we experience both the apparent reality and unreality of the photograph; other times we only experience the apparent reality and, without further examination, will not discover that we're looking into a mirror-world.
Defining cheating is not easy and depends on the photographer's intent and our conventions and expectations.
"When does a photograph document reality. When is it propaganda? When is it art? Can a single photograph be all three?"
I don't think anyone really expects advertising and glamor photographs to represent reality and we accept a great deal of manipulation in these.
In general, I don't think we realise just how distorted those photographs have become. In general, I don't think we get the opportunity to see just how distorted those photographs have become.
2. Take the original photo and clone out the mess--is this a cheat?
Mark Schacter's essay was somewhat defensive on this point. We might read PERSON 1's "Isn’t that sort of cheating?" as - isn't that sort of cheating other photographers who actually did the hard work to be there for those fleeting moments when the landscape was luminous.