Can a historian help me with this?

I keep seeing this photo pop up every now and then, but I m not quite sure what it s completely about. It s a political cartoon of Otto von Bismarck and Pope Leo XIII playing chess, and the description is called "Kaiser Wilhelm II visits the Vatican 1888". I tried researching this, but an entire novel came up rather than a simple wiki page. Can anyone give an explanation to the relevance of this?