First, it's the devotion to what he/she does. A true photographer would be, of course, in love with his own art, like an artist.
Second, it's the patience. Ideas that artists get don't follow schedules. Sometimes, on random days, they suddenly get inspirations. For a photographer, the ability to not lose his/her temper when there is not a proper scenery is same of an artist's. He/She is willing to wait until a perfect moment suddenly arrives.
Lastly, it's the precision of the hand. Artists are able to control their hands so it's not shaking as they paint. Imagine what the painting would look like if the artists cannot keep his hands still while drawing lines. Like a photographer, he/she has the ability to keep still so that the picture will be perfect, unlike a typical person who will have a hard time taking a picture because his hands keep moving.