Portraits are a representation of one's face, by another or as a selfie. Later in the history of art, half and three-quarter length portraits were added. But when the artist peeps at the subject, well, that is another issue. I will explain.
As humans, it should be very clear as to what is right and wrong. [Halt! Not always] In the realm of art, it is most interesting to learn the lesson from an allegory. I will discuss these worldly and otherworldly aspects.