There are several ways to skin a cat.
The cleanest solution if you have already been indexed to to send signals to get those URLs removed from the index. e.g. 404, 410 or a noindex meta tag.
Once the GSC is reporting all URLs as excluded and not indexed, you can do a stronger block. e.g. disallow in robots.txt or even restrict access to the whole site in ...
Some Tips if you are trying to control what appears in the local mobile search results
Make the image the first image in the main content area and make it
central to the page content
Make sure that the page is topically
relevant to your targeted search query with good architecture including title Tags & H1 tags.
Some possibilities that ...