Gmail Gridview feature overview
|Knowledge Article Number||000213079|
In March 2014, Gmail released a new feature that allows users to see thumbnails of their promotional emails. Rather than the traditional List View, Gridview shows an image defined in the content of the email in a grid layout.
Gmail Gridview shows the emails in the Promotions tab as thumbnail images. The maximum size for the image is 580px x 400px. The image can be designated in the HTML's code. For more information, please review the following documentation: