With Google AMP, your content has the possibility of appearing inside the new Top Stories Carousel - a new rich, AMP-only snippet that Google has activated in over 12 countries now.
Any opportunity to be included in Google’s Top Stories Carousel would maximize your exposure and bring your content to new users. That type of promotion could only lead to increased revenue and a bigger audience.
In order to take maximum advantage of Google AMP Rich Cards, all your articles should contain an image in order to be included. The image should be representative of the article's content and only a marked-up image that directly belongs to the article should be specified.
- Images should be at least 696 pixels wide.
- Images should be in .jpg, .png, or .gif format.
- Image URLs should be crawlable and indexable.
If you want to learn more, follow this link to see the official documentation: https://developers.google.com/structured-data/carousels/top-stories?#markup_specification.