I doubt that this Gabe Newell shield gives any statistical benefit, but seeing Gabe's face protecting you in-game must give you some sort of confidence/performance boost in Dark Souls II, right?
And yes, that's in-game texture, not a Photoshop—it comes from Peter "Durante" Thoman, a popular modder for the first Dark Souls. Writing for PC Gamer, here's what he has to say about texture modding in Dark Souls II, in case you're curious:
I'm looking forward to some talented artists trying their hand at texture modifications! However, they generally shouldn't be as impactful as they were in Dark Souls 1, given the much higher average texture resolution in the PC version of its sequel.
One interesting thing I found out while texture dumping is that some of the game's armour textures sport a massive 2048x4096 resolution, easily on par with everything I've seen in any PC title before. Certainly not a texture you would create for a game primarily targeted at running in 1280x720. Another fact I learned during the development of this mod is that high quality shadows use a 4096x4096 render target. Pretty good!
You can read more about Thoman's thoughts on modding Dark Souls II here. I for one am already looking forward to seeing what modders do with Dark Souls II once it releases for everyone.