El Greco's Portrait of a Cardinal is not nearly as obviously Manneristic as some of his other paintings, right? where there are tons of Mannerism all over the place -- elongated limbs, strangely distorted anatomy, heightened emotionalism expressed by these distortions and the expressions on the figures faces, and even by the colors.
The Cardinal is more tame. Or, at least appears to be. But is he? Is it really a quieter more Classical (what the Mannerists were reacting against) painting.
I'd say, no, not really. Although the hands are quietly Manneristic -- the fingers being a little too long and languid, I'd say the stronger element of Mannerism comes through in the crazy colors of this painting. They are fabulous colors, but they are strange and dissonant (the red/pink of the robe against the orange-y print behind him), extremely heightened and contrasty. I mean, what kind of light would that man have to be under for his robe to be THAT reflective and contrasty? The answer is no natural or artificial light: It is an invented light, invented to heighten the strange emotion and color in this portrait.
Speaking of the strange emotion, check out his expression. Is it the dignified expression that you'd expect in a portrait of a a cardinal. No....I don't think so. It's odd and awkward and internal. He's not even looking at us; he's looking awkwardly off to the side, or more like it, INSIDE. He looks troubled, doesn't he.
Also, why are his hand practically white like the hands of a dead man? Well, flesh in Manneristic portraits is often quite white. But this man's face has blood in it; his face is more naturalistic flesh tone. Strange, huh? I do not know the answer to this, but it's notable and has probably been written about somewhere.
Also, I'm pretty sure that paper sitting on the floor is written about; I forget what they think it's about.
But my bigger point is that, yes, even though at first glance, this does not appear as "Manneristic" as many other El Greco paintings, it is. It's totally eschewing a classical approach to immortalizing such an important man, and it is doing so in typically Maneristic ways,albeit with inimitable El Greco-ness.
El Greco was a strange and great painter. Some of his pictures are almost ugly. But the more you look at them, the more you come to appreciate the beauty in that ugliness.