MediaWiki:Promote-upload-additional-photos-explanation

These images are secondary images that appear in a horizontally scrolling bar at wikia.com. Like the main picture, minimum dimensions are 450px X 320 px, and only the .png format is required. A maximum of nine additional images are allowed. From a copyright perspective, it's probably best to use PR images published by the BBC at bbc.co.uk/doctorwho.