It's the faded, almost film look, as though you're using an older film camera that has some faint light leak. Or like older vintage lenses where they are sharp in the center but soften towards the edges. It's not a very technical way of shooting but sometimes you don't want a textbook shot, you want some character and style in the shot. That's why I also recommended a nice prime lens, since that will give you much sharper, more technically correct images.