My second impression is: Why must all artists depict drow the same way? Isn't a major aspect of art (and D&D, for that matter) to come up with your own version of something? To make it your own, whether you're an artist or DM or player?
Artists have depicted dark elves in alllllll kinds of ways for a while now. A quick pinterest search shows this.
But until recently, dark elves in D&D, specifically, were the drows; evil looking, underground dwelling, black skin, white hair, matriarchal, spider-worshiping elves. So artists auditing for D&D art, or commissioned for D&D art, represented drows according to these artistic guidelines. This monolithic artistic representation was coherent with D&D's monolithic description of the drows. It looks like there was a recent and deliberate shift in this paradigm, so you should expect more variety from now on.
Nevertheless, D&D will always keep some kind of guidelines in their artistic direction. At least I hope they do. The trick is always to set the proper range in variance. For example, I'm not sure I'd be cool with something like dark elves having anywhere from 1 to 5 eyes, because diversity! 1-5 eyes dark elves can be cool, but let it be setting-specific. Exaggerated example is exaggerated, but it illustrates what I mean.
FWIW, I would have preffered that dark elves had kept their black skin, and evil Lolth-worshiping matriarchal drows were made a setting-specific drow nation among a few others, and were given a more neutral description in "core" D&D PHB and following supplements.