Public playlist not showing an image in search

[Mathaus]

Is there a reason why my playlists are not showing the usual image (first 4 tracks) when searched? 

[Peter__]

Are the first 4 tracks in the playlist local files on your computer?

[Mathaus]

Hey Peter, no...actually none of the songs in the playlist are local files.  

I think the issue could be that even though the playlists (some created in June) are set to public, they are not showing up in search and can only be seen by me since I created them.