What makes a good photograph?

Have you checked out the Head On Festival in Sydney. You really must. Just opened last night at the Gaffa Gallery on Clarence Street is an engaging exhibition featuring some wonderful photographers across two levels.
Early in May as part of Head On, Magnum photographers Shahidul Alam and Eli Reed, along with Benjamin Lowy, recipient of the Magnum Foundation Emergency fund, suggested a good photo has the following characteristics:
“Telling stories. It is what it does to people that matters. Is it going to bring about change?” (Lowy)
“Ambiguity and encouraging questions, as well as to tell stories. The photograph asks more good questions than it answers.” (Lowy)
“It is inherently captivating. There is a truth and beauty about the story.” (Lowy)
“When things are photographed in a particular way, what do we lose? Complexity of the stories often doesn’t come across when we provide a simple rendering.” (Alam)
“Be a fair witness, not overdoing it, otherwise you will mess it up…Look at what’s happening. It’s not a game, but it is the ultimate game. Pay attention.” (Reed)
“Fascination with life. That is what it means to be a humane human being. Being a human being first (not a photographer). It is it’s own reward.” (Reed)