This is the cover image to The Chivalry & Sorcery Sourcebook, drawn by Mike Gilbert, which I look at quite often, since the book it graces sits on my desk. I'd never argue it's a particularly noteworthy piece of gaming art, but I've found that it's grown on me a lot in the weeks it's rested on my desk. A big part of its appeal is the wizard on the far left, the one with the skullcap and sunglasses. At first, I thought he was supposed to be a cleric of some kind, but there's nothing "priestly" about his attire. Indeed, his attire is pretty non-descript (though I do wonder what that thing he's got on his right wrist is supposed to be).
So, what's up with his spectacles? I honestly don't know. Eyeglasses existed in the Middle Ages, so it's not necessarily anachronistic to include them, even if the style used in the illustration looks a little too modern. Of course, they look more like sunglasses than simple eyeglasses, so that raises other questions. On the other hand, maybe they're magical lenses of some sort, like those found in Vance's Dying Earth tales, though I don't recall ever seeing such magical items in C&S. I'm not personally bugged by it; in fact, for some reason, I don't find the notion of sunglasses in a fantasy setting to be off-putting at all. I bring this up only because the impression one gets from reading Chivalry & Sorcery is that its authors would be annoyed by such a blatant anachronism.
Regardless, I really like this illustration.