How to code webpage photos so they can't be pulled as thumbnails for the page link?

Is there any way in SiteBuilder to code some of the photos on my webpages, so that those photos would not come up as usable thumbnails when I post a link to the page on Facebook or in other venues? On one of my pages, I have 4 photos plus a clipart I imported.

When I post a link to the page on Facebook, they offer me 3 thumbnail options from my page, but none of them are the photo I want to use (the actual cover of my music CD). I don't want to delete the other photos & clipart from my page (they have function and bring flavor to my page) in order to narrow down the thumbnail options. Is there any other way? Thanks!