|Greetings from the Critique Club!
Great capture of an animal in its own environment - I could tell from the first glance that this was no zoo shot. Love the focus on the head, can just imagine how you felt when you met it. The sinuous body, the duckweed on the surface of the water, the natural lighting, good comp, though maybe a little more dof would be good. Shooting wide-open is pretty dicey esp with such a shallow dof.
But DANG! That branch! That is definitely a big part of what killed your score imnsho. As already noted, it decapitates the snake and thus robs it of some of its power. That, coupled with the DPC voter fraidy cat voting when it comes to creepy-crawlies and not kutesy kritters or majestic felines/raptors etc....*sigh*
Still, a very good image. Maybe just a little more pp contrast would have helped, but cloning out all of that twig would have been a major pain in the butt.