When you notice that you've got the wrong image paired up with a playlist item, or the cover art isn't permitted (violence or nudity depicted), you can change it!

Go to your Workshop and visit the Playlist tab in your Partner Dashboard. Click Change Cover on any items that you need to update, choose from the list of alternate images or set the Station Logo instead:
​

When you get to the bottom of the list you can load more results:
​

Have fun!!