Okay but I own the ring, even I'm not holding it.

Well... No, the ring is Sauron's for legal reasons. You own a picture of it on the shared ledger.

Okay, so I can expect this picture to be under my control and ownership at least?

Well... No, you don't "own" own it, and it's not the picture either, really. It's just a number. But! The number points to a row in Opensea's database of pictures.

Okay, so I have ownership and control of that picture in Opensea's database?

Hahaha no, they can remove it or change it and you can't do a thing.