Raising Shoulder Upward Toward Cheek?

[sparky]

So I see some top shooters lift their shoulders upward toward their cheek. I normally don't, but I figured I'd give it a try a few times.
Maybe it's because my shoulder is weaker, or I'm just not used to it, but I'm not seeing any benefit...just increased tension and fatigue in my shoulder.
What's the theory behind it?

[CamelNL]

Less head tilt, you can keep your neck and head straight up. Its a bit the same as in rifle shooting with sight elevation.