We’ve seen Google ask searchers if they are satisfied with the search results before. Using smily faces or other forms of voting. Here is a screen shot asking searchers if they are satisfied with the news results in the top stories within search.
Valentin Pletzer shared a screen shot of it on Twitter, here it is:
Again, Google has done this for probably 10+ years in the search results in numerous ways. Here Google is doing it for the top stories section in search on mobile.
Forum discussion at Twitter.