Before getting to why I really like this I just want to praise some of the technical things about this photo. First, the lighting. It's bright enough in the right places to emphasize what we need to see, but the shadow creeping in is really fantastic, like this girl (creature?) is emerging from the darkness for us. Or maybe even sinking back into it, who knows? But I really like that, and the half-shadowed face really emphasizes the gore quite well. The blood also looks really good - it's a nice color and it looks nice and messy and sticky and gross, it's very real. Especially the way it looks around the eye, that sticky messy kinda look, like it's starting to dry a little, really awesome effect. I think the composition is mostly good, but if it had been slightly wider, with the eye fitting more into the rule of thirds, it would've been perfect - however I don't think that it takes away from the impact of the photo.
But okay, my favorite thing about this is the eye. It's what makes this photo different from the million other pretty bloody girls photos that we see every day - it means something's happening right now, or that this is some type of creature, or monster, or victim, or what?! It's so creepy, and the detail looks excellent, the little vessels are perfect and match the blood so well. So what really stands out about this image is that it's mysterious because of all this, it isn't just gratuitous gore because it's not entirely natural, and when you look at it you have to wonder what the hell is going on, and having it inside your brain like that is really haunting.