Dear CodeBard, thank you so much for your clear explanation.
As for indexing, I think you are right. So, things remain as they are.
Regarding the “Enable Image Lock” function, I have never activated it. I have checked the image detail page in the WordPress admin panel and it is visible to everyone, as a Patreon plugin setting. If the image blocking function is disabled, I wondering why the featured image is not visible to everyone at the top of the post?
Thanks in advance for your kind responses.
Best regards,
Flora