Tons of skin showing, exposed cleavage, Sayori most likely grabbing that ass, Yuri blushing because Sayori most likely grabbing that ass

Tasteful? Not sexual? These words are meaningless in waifu world and strangely enough meme world as well

They're in regular swimsuits, and that implication of Yuri and Sayori is your own interpretation. I see it as Sayori's regular sprite pose, and Yuri blushing since she's normally reserved.

If you find it lewd/hot, then that's fine but I find it to be relatively tame and nice fanart of the girls enjoying a day swimming.