Ngl if women wearing bikinis is, in and of itself, considered sexual, then some people are definitely porn-brained and should not be allowed anywhere near beaches.
"hiccup is aromantic and Astrid is a lesbian" you say that as if it's been confirmed at any point within the series. I would've respected this if you just said this was your own personal headcanon, but this is just delusional ngl
There's a fine line between "cute sexy" and pornography, and if you're trying to imply that the artist drew this with the latter in mind, then that's a you problem.