For me, unfortunately, this solution approach is not helpful in the long run. In my opinion, the way only helps if the note does not need to be supplemented further later. But even if the note was not changed later, I have noticed with notes with many images that the thumbnail sometimes selects itself again independently from the mixture of images.
I regretfully continue to consider it a big problem to provide a preview with an arbitrary thumbnail by EV.
I create a lot of tutorials with screenshots, and I want to be able to tell which tutorial it is by looking at the thumbnail. For example, if I were to write tutorials about cooking recipes, I would naturally want to have the dish selected as the image for the thumbnail, and not just any ingredient.
For presentations, I actually don't use Evernote anymore because I'm embarrassed to get such useless search or display galleries.
Hope dies last. I'll keep my eyes open for other solutions.