How we cite our quotes:
Quote #1
"I don't care what they call me," he said confidentially, "so long as they don't call me what they used to call me in school."
Ralph was faintly interested.
"What was that?"
The fat boy glanced over his shoulder, then leaned toward Ralph.
He whispered.
"They used to call me Piggy!" (1.65-70)
Before the boys reveal their names, they are identified by their appearances. Ralph is "the fair boy" and Piggy the "fat" one. But Piggy's name itself refers to his weight, which means even back in the civilized world appearance determined identity. We might feel better knowing everyone's real name, but is there really a difference between being called "the fat boy" and "Piggy"? Aren't they really the same thing?
Quote #2
Jack planned his new face. He made one cheek and one eye-socket white, then he rubbed red over the other half of his face and slashed a black bar of charcoal across from right ear to left jaw […]. "Samneric. Get me a coconut. An empty one."
He knelt, holding the shell of water […]. He looked in astonishment, no longer at himself but at an awesome stranger. He spilt the water and leapt to his feet, laughing excitedly. Beside the pool his sinewy body held up a mask that drew their eyes and appalled them. (4.31-33)
Jack is as excited about his new identity as we are about getting a great new haircut. Sure, maybe he's just excited because it's a cultural taboo. Then again, maybe he's excited because he knows it's going to give him power over the others.
Quote #3
He giggled and flecked them while the boys laughed at his reeking palms. Then Jack grabbed Maurice and rubbed the stuff [blood] over his cheeks. (8.195)
After the boys kill the mother pig, they smear their faces with her blood. First things first: ew, gross. But it's also smart. The blood becomes a mask that distances the boys from the event. If they don't feel like themselves, their actions don't seem as horrifying to them.