Question about the fawn scene

He's identifying with the innocent, unsuspecting animal, another victim of the senseless violence to which he finds himself subject. More generally, he's identifying with, and embracing, the inescapable death that surrounds him.

The way I interpreted it was as a way of showing his spiritual progression; he sees the dead fawn which died needlessly and deeply connects with it in spite of it being "just a dead animal". This scene probably has multiple layers, one of which is him bonding with it posthumously on a spiritual level in the sense that both life & death = energy, and the belief that spiritual energy or entities can reside in many aspects of nature itself. His action of taking its blood and wiping it on his face was to deepen that connection but also empathize with it on an immediate physical level as well -- the fawn died for no reason during the hunt for his bounty, but Blake himself is being hunted for all the wrong reasons and is essentially an innocent man whose fate is an impending untimely demise.

Also take note that prior to this, the substance that Nobody originally smeared on Blake's face gradually dissipates as the film goes on, to the point that it's all completely gone by the time he dies and passes on to the realm of the spirits, as Nobody said. I took this to be clear symbolism for his remaining time in the world of the living before his flame finally settled at the end.

And, it's a cool looking shot.

"What can be asserted without evidence can be dismissed without evidence."