Google is testing a new format for the news carousel that lets users swipe between categories of news. This new carousel will show both AMP and non AMP news in the top news section.
Here is a picture of the toggle version of the top news carousel:
Here is an animated GIF of it in action, where you tap on the arrows at the top to flip between news categories:
To replicate, just search for [news] in Google on your mobile device.
This was first spotted by @christian_wilde and I think it is new.
Forum discussion at Twitter.