What is pictured is cruel, and not even on the same page as a predator killing it's prey, unless you compare to a cat playing with a mouse, allowing that mouse to die a slow agonizing death (in which case the mouse may be considered a toy more than prey). This is more like putting 2 dogs in a ring and expecting them to fight.

When a predator kills in the manner it was meant to, there are mechanisms at play that help keep the prey from suffering too long before it dies. The prey may go unconscious, or adrenaline or other hormones may prevent it from feeling the pain until it does fall unconscious or dies. Not the case in a slow torturous death such as this where adrenaline would wear off before consciousness subsided or death overcame the snake.

Also, movement and even sound isn't a good way to judge consciousness or death. If you cut off a chicken's head, it is dead, but the body will continue to move, violently even, and it can make sound (sound is produced in the bird's lungs not throat like in mammals) even after death gas occurred. There is no consciousness, the heart may no longer beat, but the nerves still send signals that cause movement. Sounds can be produced simply be compressing the chest. I've seen and experienced this before when butchering chickens for consumption. The phrase "running like a chicken with its head cut off" is actually based in fact!