The glow is more of an over all thing. I kind of gives it a 'softer look' though there are still a lot of shows that have really crisp art work too. How I do my 'softness' is in Photoshop. I combine everything into a new duplicate layer, Blur it a bit (I use gaussian blur) generally just enough to some what distort the image but where you can still see whats going on. and then either overlay it, or use soft light.
Heres a good tutorial on the screen shot thing over all. [link]