NFT ... If u don't know now u know

Hi everybody,
Here’s the news

-I’m not a working developer, I’m more research related, but I thought this should alarm the Ethereum community to change things somehow.
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-Now let me tackle my own questions about NFTs, that I posted in many related topics suggesting new standards or enhancements to ERC-721, ERC-1155 but I did not get any clarifying answers:
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1-What is the underlying cryptographic hash (someone did say in his/her reply it’s SHA256, but with no reference)?and more important how it’s accumulated or aggregated for connected objects?
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2-The degree of security depends on the object kind and to what limit it could be uniquely identified, ie I still see u can’t just sell they’re all the same level of security.
Ex.
-if u sign a real estate contract with say SHA256, then ur ownership is as secure as SHA256
-but if u used it to sign a photo or even a DNA, u should add to ur calculations the accuracy of ur presentation of the image(the way u uniquely identity it), or the accuracy of DNA (I know DNA is like 0.9999…9 accurate)
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3- For this specific case of the Beeple pic, as it includes smaller images inside it, I’m asking what exactly did they hash?
*If they hashed every small image, howcome one of the smaller ones got a new NFT?
https://t.co/Vfh9E108SG?amp=1
Uploading: Screenshot_2021-05-31-09-50-16-79.jpg…
I know it’s a joke, but it seems he did made a new NFT after a simple edit, didn’t he?
*If they did not, do u think the owner who paid 69m$ is aware of that?or thinks he bought them all?
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4-What about modified in the original object?The hash will clearly (most probably) change, for the Beeple image I know I’ll try to explain the fact that NFTs r digital. What about real objects?VR of real objects???
-For example antiques or museum pieces?if someone say draw anything with a temporary or an erasable color, will this change the NFT?I mean it will probably change the hash?

-For the museum case the two last questions r popping up; u may need an aggregated hash connecting all pieces in addition to each piece, and u will also worry about a thief making a slight change to the piece hash and sell it in International auctions (in a way like the Daily Show pic but more slight & professional)
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-Lastely, since the BBC news is about a VR object is making an NFT to museum pieces reserve the copyright of their VR?