> took that image from the online shop
They didn't take the image. They looked at it and learned a few datapoints from it. It's not like they compressed the image and added it into the model, able to be reversed by anyone who downloads it. In fact it's likely there's other completely distinct images that could have contributed the exact same tweaks to the model, like a hash.
>I can enter a bookshop and look around, open a book, read some pages and maybe learn something.
>It doesn't give me the right to republish a similar book putting together what I saw, unless the license specifically grants me that right or I obtained a license that does.
No, but the analogy would be if you learned something from the blurb you read - like a word, or a factoid, or an expression - and it influenced some writing you did later. You didn't steal from that book's author.