Notice how the features of this artist's face align appropriately on each side of his center line.      
    This student perfectly matched the shape and colour of her eye, as well as mastered the curve of her nose being perfectly symmetrical.  
Not only did this student master the shape of his face and the angle of his jaw, but he also did an excellent job of showing the symmetry in his eyes, nostrils and lips and their distance from the center line.  
    Notice how this artist put in an effort to show his open mouth expression, as well as aligning his eyes.    

Copyright J.Lambrinoudis and M.Shervey