What is the significance of the title painted faces and long hair?

The title speaks both literally and metaphorically to changes in the boys over time. Jack paints his face to hunt pigs, believing that his success depends upon the pigs not be able to see or smell him. He plans the painting carefully, using charcoal, and when he sees himself in the water..... he's astonished, like he is looking at a stranger..... a dangerous, frightening stranger. Jack is, in fact, transformed, and in response he begins to dance savagely..... snarling, hiding behind the mask of his own creation. This transformation is also the first instance of true savagery in the story.