When I first looked at it,I thought the blade would sit up on top of a sidewalk that runs parallel to the curb,and pull the snow off the sidewalk,and into the lot.I know i could use something like that at a few places.
But after looking at it again,I'm not sure.

I guess it's to stop snow from being dumped onto the walk when cleaning up along the curb.It would also be nice,as you wouldn't get as much spillage off the one side when working across long lots,eliminating the need to make another cleanup pass.All most like windrowing with a regulaqr plow blade.
Kinda makes me think of those new Storm plows,with the wings.They are awesome.