Several images on Commons are automatically protected from edits for a short period of time due to their visibility.
Main Pages 
Most wikis have indefinitely restricted editing of the Main Page for administrators only. This protection cascades down to all pages, files and templates that are embedded into the main page. However this protection is limited to within the wiki. The following pages serve to forward this protection to Commons for the files that are embedded onto those pages.
Certain images are used outside wikitext, but are highly visible. Such as the configured
$wgLogo of a wiki. Things like that are monitored under this section.
Manually updated with the help of the wgLogoUsage tool.