these are artworks. Did you ever see the concept artworks for the intro scene of CMI? They didn't look like the real scene. It just depends on the style he wants to use depending on what he needs it for. Just for showing, how these characters may look like, this style is good.. And you don't know for which MI this is. I think these MI-Paintings were created for one of the "sequels" but those scenes never got into a game. I don't like the comic style for MI, but I don't think, that I would like a dark reality painting of MI.
Mentioning MI1: You know, that Mister T. looks very young there. In those paintings it's the same. Where do you see the comic then? It's just that you know:"AHHAHHHHhh MI is comic-like now, so the paintings are, too". Ever checked other concept artworks? Some of them look comic-like but afterwards the game is more realistic than comic.