I would say there are three main elements of game mechanics: 1) rewards or penalties; 2) unpredictability, either through interaction with other players or pure

I would say there are three main elements of game mechanics: 1) rewards or penalties; 2) unpredictability, either through interaction with other players or pure chance; 3) utilizing player skills that can be improved with repeated play experience. None of those are involved here, except maybe a little bit of 1) if you consider +1 a "visual reward". I'd really expect all three to be involved before saying something has game mechanics--you can easily find each of them in Foursquare, for instance.