Hashtags are common on many social media platforms these days. With regards to Google’s own services, Google+ had hashtag support before it was shut down, and YouTube has them for nearly three years at this point. Discover is the latest Google service for experimenting with hashtags, although it seems a bit redundant.
The implementation in Discover is somewhat similar to how YouTube shows them, with a few hashtags appearing at the bottom of each card. In my opinion these hashtags are rather useless; the title tells me much better whether I really want to read the article or click on the video.
That said, if you want to see more content about that hashtag, you can tap it to see more relevant articles and videos. Tapping the #FlatSixEngine hashtag in the above screenshots shows a bit more content that Google thinks you’ll like, but in reality, I doubt people are looking for stuff to read or watch that way.
For now, these hashtags seem to be part of a fairly limited A / B test. I personally hope they don’t go official as they just add junk.