Place the rotating comet demo or black comet demo and either the earth or moon globe in the light from a slide projector.  Note how the light colored or shiny globe reflects much more light than the black spongy comet demo or the black surface on the rotating comet.  If you wish, you can look at the reflected light from the objects with a light sensor to produce a light curve.  

Hold a crumpled and flat piece of aluminum foil in the light from a slide projector.  Note how the flat shiny surface reflects much more light that the crumpled ball.  A light sensor may also be used to produce a light curve of the high albedo object.