The idea is to have an option to make the extension only replace thumbnails and titles for pages you have enabled.
For example you might want your subscription page to not be modified, as you probably can tolerate the content posted there and want to keep the creators original intent intact
Seems to work kind of ok now, but thumbnails are often cached across pages, thus not making a new web request for them when you switch pages. Not really sure yet how to stop that from happening.
The idea is to have an option to make the extension only replace thumbnails and titles for pages you have enabled.
For example you might want your subscription page to not be modified, as you probably can tolerate the content posted there and want to keep the creators original intent intact