Lately, there have been multiple uploads of pictures that are extremely bad quality (i.e. dark, blurry, unnecessarily cropped, stretched, etc.) and one of the biggest is pictures that have logos.
These are unacceptable and the user who repeatedly uploads these will be given warnings. If these warnings are ignored and the user continues to upload these - they will be blocked. The admins are tired of constantly needing to remove these pictures in order to keep the Wikia tidy.
The rules have also been updated, read and review them: Help:Winx Wikia Standards. Pay close attention to the rules for the pictures and gallery as it is these two that have changed.