A portrait is a painting, photograph, sculpture, or other artistic representation of a person, in which the face and its expression is predominant. The intent is to display the likeness, personality, and even the mood of the person. For this reason, in photography a portrait is generally not a snapshot, but a composed image of a person in a still position. A portrait often shows a person looking directly at the painter or photographer, in order to most successfully engage the subject with the viewer.[from wikipedia]

Wall comes from Latin vallum meaning "...an earthen wall or rampart set with palisades, a row or line of stakes, a wall, a rampart, fortification..." while the Latin word murus means a defensive stone wall. English uses the same word to mean an external wall and the internal sides of a room, but this is not universal. Many languages distinguish between the two. In German, some of this distinction can be seen between Wand and Mauer, in Spanish between pared and muro.[from wikipedia]