Pareidolia is a psychological effect where humans see patterns in objects where there is not meant to be a pattern. This is most frequently faces, the human brain is fantastic at spotting faces where there isn't one. We’ve all seen cars, houses and plug sockets that look like faces.
It is thought that this pattern making by our brains is an evolutionary hang over to help us respond quicker to potential threats. Now it can just lead to mirth as we find houses and even kettles that look like Hitler and ever so happy plug sockets.