"Though this picture is simple. I have done black and white photography for many years and my favorite element of design is contrast. The contrast in this photo takes it from simple to interesting." I think this a fine example of contrast/black and white.
Self portrait ideas Mapping 2013 on Behance Use a process like this for "identity/self-concept" activity about skin color/shade/tone/palette. Put vertical photo strip of every child together on a couple images to make a collective face.