I don't see it a lot different to insta-culture with airbrushed photos and unobtainable / unrealistic representations of women that many girls aspire to and of course can't be cos its not real. We KNOW this is damaging to girls.
Anime representations aren't hugely different in that sense. They are clearly fantasies but also aspirations too. They are often overly sexualised and have extreme gender stereotyping.
There's definitely an 'ideal' representation of 'male' and 'female' in both though. It think its possibly part fantasy but also simply part alternative to mainstream lifestyle. In the same way that Goths very much were - but sexualised.
Anime is also about online communities and online relationships / indentity. You can be someone completely different on the internet - so it also has this element of 'disassociation' of identity.
But I'm not sure its that different to filters and photos taken from odd angles in terms of being unrealistic. Its just alternative.
I think I find it fascinating though, because it highlights its cultural and not innate though. Its a socially driven phenomen and the anime actively being a theme shows it though, and thats why I think its important to note. If trans is innate you'd expect people to be into a vast number of different cultural things and different politics. Not all into the exact same shit.