This picture is used in the book "Seven habits of highly effective people", written by Stephen R. Covey , to describe that two people can see the same thing, disagree, and yet both be right. It´s not logical ; it´s psychological . Covey writes: "Each of us tends to think we see things as they are, that we are objective . But this is not the case. We see the world, not as it is , but as we are -or, as we are conditioned to see it. When we open our mouths to describe what we see, we in effect describe ourselves, our perceptions, our paradigms." This means that we often have disagreements depending on some strange thought that we are right and the other person is wrong, when maybe both are right - due to having different experiences and beliefs. To read more about "seven habits", go here ! Finally, which woman do you see? The young, good looking or the old hag ? Why?!