We just got this yesterday & thought we’d let you know. The new format is called Collection Ads!
“Facebook’s new mobile-only ad format combines a big header image or video with four product images in the news feed, which opens to an immersive fast loading shopping experience with up to 50 shoppable products when you click “More”. Think of it as a scalable way to create a fullscreen experience like that of Canvas using a product feed. ”