I find it strange that in this day and age, people are still so heavily focused on racial stereotypes it puzzles them to see a screenshot of one elf looking a little like a guy from another elf tribe. Face it, people can actually look very much like they belong to a totally different race. This goes as far as white couples having black children, so I really don't believe a Bosmer with somewhat Dunmerish skin is reason enough to doubt the existence of the universe.
It has nothing to do with that. It has to do with the established appearance of the Bosmer and the claims about each race looking unique not quite matching up with what we're seeing here. We have two, not one, but two Bosmer screenshots, only, and both display a kind of Elf that is shockingly strange-looking by all accounts pertaining to them in previous games. They resemble a a type of Elf they, according to past experiences, should never resemble. Chimer and Altmer looking similar was never contested because that is how they have always been like since the inception of the Chimer race in the Elder Scrolls universe. Now Bosmer... I don't think anyone expected them to be so revamped that their eye and skin tone are similar to that of a Dunmer's. It would be like seeing an Imperial with green skin.
It's nothing to do with racial stereotypes. If I took myself as an example, I know few people would ever be able to guess my heritage just by looking at me because nobody's ever got that right by just looking at me. That's not a problem, though. That's just the way it is with plenty of those sharing the same heritage, yet the stereotype of what I should look like in the Western world just says otherwise... but I'm not a video game character whose heritage's physical characteristics have been represented many times through past games in a very different way from how they now appear. Bosmer are not real people. They could be made into red dragons if Bethesda wanted, so this "discovery" of grey, red-eyed Bosmer is not some case of a stereotype proven wrong, it's just a complete contrast to what the Bosmer have always been.