I suppose if (insert luxury fashion label here, let's say... Gucci) has an online store on Zuckverse, and also has one on TimCookVerse (where the plebian green bubble people don't come), they would allow owners of virtual Gucci bags free copies of their virtual bag on 2 different platforms.

Yeah, it's a ridiculous idea of the future, where people who currently walk around with $5000 purses ($20 for the utility of "it carries my things", $4800 for the brand name) will in the future be pixels on your VR googles walking around with $5000 pixel representation of purses, which you can right click, click "Properties" and confirm the digital certificate of. I've so far been an NFT-ignorant, but are those NFT exchanges the ones who want to be the digital certificate authorities? Couldn't Zuck or Cook just roll out their own?