Since the best result a photographer can possibly acheive is to convey emotion, wouldn't that make this the best photograph ever taken in the entire history of photography pretty much on that basis alone?
Assuming I'm willing to buy into that premise; I simply do not feel any emotion when I look at the photograph.
There is one very important component to the hypothesis that you have neglected:
The viewer.
Here's my analysis:
1. Since the best result a photographer can possibly acheive is to convey emotion
to the viewer, and
2. The viewer feels no emotion when viewing the photograph,
3. Therefore; the photograph has failed to convey emotion.
Most worthwhile art is that way; it "conveys emotion", or more precisely;
elicits emotion in the viewer.