Two SEOs from India noticed and told me about Google showing them a new blue bar under some of the featured snippets that let them give Google feedback about that specific featured snippet. This is in addition to the small "feedback" link that I currently see.
They shared screen shots on Twitter, but here are the ones from @venkatthangi.
I am not sure if this is a test or a new feature rolling out. It is just a way for Google to get feedback on their featured snippets.