The question was asked why an altered thumbnail would be removed.  The likely reason is because an altered thumbnail  is considered a misrepresentation of the work.  Someone views the the thumbnail and thinks they're going to see a girl in a white bikini riding a white pegasi.  They click on it and they get something different.  Rendo then gets a complaint.  Which then sets up the damned-if-you-do-and-damned-if-you-don't.  Create a thumbnail that is a true and accurate representaion of the work and you're in violation of the TOS, create an altered thumbnail to meet the TOS and you're still in violation.  Which is one of the reasons I don't post to the gallereies.  Too many conflicts in their TOS.