Well I mean that wouldn't be a fetish. Variety has always been a thing for straight guys, its part of what makes the porn industry tick. And I don't mean that in a "men are sex maniacs" way, what I mean is looking at images or video of multiple different women actually is more arousing for most men than just like, I don't know, a longer video of the single most attractive lady.
When I said the fetish discussion is relevant to anime, what I meant is that due to market saturation, for any given fetish there's probably an anime/manga that is just about that fetish and doesn't have much else to recommend it. Most of them won't be discussed here because, well, they aren't worth discussing. But they're out there, and they maintain an outward appearance of not being pornographic which is odd.
In a lot of ways the difference between anime now and anime in the 80s/90s is the specificity. In old anime you got things like gratuitous nudity, rape threats/backstory, questionable clothing, harems, the works. Depending on the anime it could still be a fucking embarrassment, but they were aimed at general male audiences and those are things that might appeal to general male audiences. What's so strange about anime now is that even in mainstream, NOT hentai works, you get things like 12 year old fanservice characters, or casual inclusion of fetishes to a degree where its no longer a light implication. Its caused anime's reputation in Japan to go down over time, in contrast to say western animation or video games which have gained mainstream acceptance over time (or at least stayed the same).
Edit: I was responding to a later post about "fetishes don't have to make sense." The face... I don't have an opinion on the face. If was being generous I'd say its an exaggerated perspective thing? But the extreme emphasis on the teeth, well... whatever the reason, I wouldn't call that good art.