As soon as you see this kind of gas counter in Spain, you start noticing that its design is pretty similar to a face:

A face likes this:

And then you see a similar device with 3 counters, which you recognize as a "3-eyed face" (see also the native american version):

Later on, you encounter one-eyed faces such as:

Or the wounded version:

Why do I blog this? These observations are close to a phenomena we described with Fabien in Sliding Friction: Mistaking an interface or a device for a face corresponds to a psychological phenomenon called “pareidolia”: a type of illusion or misperception involving a vague or obscure stimulus perceived as something clear and distinct.

Recently, I also dealt with the link between this and design... showing how Gerty, the robot in sci-fi movie Moon had a pretty basic face cued by a display that showed a smiley. It's fascinating to see how very minimal features can trigger (1) a face-like appearance, (2) rough forms of emotions that individuals can project on the device.