Cameos ties into the Posts on Google tool, as TechCrunch notes. That platform lets the likes of celebrities, politicians, sports teams and local businesses share tweet-like posts in the knowledge panel on their search result pages. The knowledge panel is the section that includes key information about the person or organization you're searching for, often including links to their social profiles.
Users of Cameos will see the top queries people want answers to, seemingly including questions asked specifically about them in search along with trending topics they may wish to weigh in on. Google will add more questions on a regular basis, and among those offering their responses so far are Golden State Warriors star Kevin Durant and model Karlie Kloss.
Access to Cameos is by invitation. If you're interested (and think you have sufficient social cache), you can download the app to request permission.