text: Way other way computers would provide specific answer like angry, happy... is by knowing the parts of the body to identify the positions of the bone. Emotions as we know can be told by looking at the face at an individual face, on paragraph 7 it says "while looking at the mirror: raise your lips at the cornersof your mouth, then squint your eyes slightly, to produce wrinkling ("cow's-feet) at the corner of your eyes, holding that, raise the outer parts of your cheeks up. toward your eyes" basically the computer has to identify parts of your body to detects the bones which can produce excellent result.