You don't get it at all.
Why do you 'photographers' have such an inferiority complex, that you feel inferior to artists (which means painters and sculptors), and must co-opt the label 'artist'? If photographs are not works of art, so what?
You seem to believe that if a photograph is extraordinarily beautiful it becomes a work of art. If a horse is extraordinarily beautiful, does it become an elk?
The work of art would be in how that horse was captured in the photograph. The lighting that was taken advantage of or used, the way the backround was chosen or taken advantage of and treated etc..
there are a whole slew of choices that can take a simple horse ( how simple is a horse though, I consider it a work of God's art ) standing in a field and turn it into an image that strikes emotion in people. A freekin slew of choices, angles, treatments. Waiting for just the right time of day or even season, which angle, high low dead on .... which lens what aperture, how close. what pose for the horse do we wait for ? Maybe the photographer ( artist ) waits for the horse to have one nostril flared and his right eye closed and his left leg lifted. I don't know. You get the point.
How is the horse framed in order to create the desired effect ? How much negative space to use.
All of these things just touch on the amount of choices to be made. And that is just at capture time. I didn't even go to the post processing options.
And I am a beginner and probably don't even know half the choices available to someone more adept at photography. Oh and then there are filters to be used, stacked for various numerous purposes.
You get the point ? Tons of stuff. And the difference between what a great photographic artist can do to that horse and what a snapshotter can do can be vast !!
To through another kink in it, maybe only 10% of the people who view that image get anything out of it ? Maybe you or I think it just plain sucks.
Who cares ? It is still art to the maker of that photograph, and is certainly worthy of being called art as much as somebody who paints a horse on a canvas.