I don't know what you guys mean... like the emerald thing whatever it is, or the sharp cut off edge of the glow?
Alright, so i messed around with the image on photoshop, and managed to create the edge to a round shape. @andrewkm you could change it to this if you would like.
You didn't. Look, your one is different, it has an enderman, that's how you know i edited mine and mine is different from yours