In this case, the picture is a close-up, and the subject of the close-up is a face. In the first picture, the subject is clearly revealed by the tonal organization. The tonal scheme allows the viewer to see the face. The subject and the tonal organization coincide, so the first picture is coincidence of tone. In the second picture, the subject (the face) is not revealed. There’s no light on the face, so the subject is obscured. This is noncoincidence of tone. The tonal organization of the shot hides the subject (the face) from the audience.