Comment by floatingatoll

I think it would be short-sighted of Google to simply count votes without recording some sort of "authenticated" bit for later use.

Counting 'votes' provides useful data for Google internal decision-making.

Counting 'authenticated votes' provides useful data for Google to publish.

Lacking any information from Google, it is unclear whether this is just a "feel good" button or if it's an actual authenticated vote-counting system.