Not the same idea at all. An NFT doesn't allow you to control the use of anything. It'd be analogous if a patent allowed you to authoritatively claim you were the first person to patent it (at least on that specific blockchain), but didn't grant you any exclusive right to use of the idea.
Who would have a legal base to hold an image of a site?
Indeed. The copyright owner if there is one and then probably the site holder.
There's no single lawful correlation between NFT's and the real world. And people are literally buying this, they don't even know what they are buying.