@Speppo82 Yeah, it's pretty confusing. Especially when the community can't seem to agree what actually separates the two.
My understanding is that the difference between Shoujo Ai and Yuri is "best friends forever"/platonic "love" versus romantic love. However, you also have the other interpretation that differentiates the two on the matter of sex. If its romantic with insinuated (but never shown) sex, its Shoujo-Ai. If there's sex and it is not graphically shown (hentai), then its Yuri.
Even so, I get faked out a lot (where they end up only just being friends) on this site and others... it does get annoying. In that regard, I really wish they could make up their mind as I like knowing when I go in, if there will be payout or another disappointment. It would therefor be nice if MangaDex set how they define the two tags and ensure that standard is used across the board so that it's obvious upfront which of the two it's going to be (love or friends).
Personally, I'm banking on lovers. Particularly with the height gap and age gap. But I've been disappointed before...which is why the Shoujo Ai tag worries me so much.