Use the rules below like a filter to narrow down the content api response into a list of candidate images. From the candidate images, choose the master 5:3 image, or simply the largest 5:3 if a master wasn't found.
- Use the trail pic (known in content api as 'image element with thumbnail relation'), if it contains an image with width >= 460.
- Use the main picture.
- Use the image from the first embedded video
- Fall back to small trail pic.
- Only use the thumbnail.
- Use the Image override if specified.
- If the card is a Gallery, use the Gallery behaviour.
- Use the default rules.