Reader view on apple news, new feature?

While reading an article in Apple News the other night after updating my iPhone 11 Pro Max to 14.2, I noticed that when I opened the full article, it opened another smaller window with the article in an in-app browser. It also allowed me to use reader view. I thought this was awesome! Then, the next morning, the feature disappeared. I still have it on my iPad, which is also really awesome, but I want it back on my iPhone.

Has anyone else seen this on the iPhone and do you have any idea how to re-enable it there?