When the children first arrive at the island, they’re required to get rid of their shoes and old clothes as part of the initiation process. The young kids will soon outgrow their current clothes anyway, and there’s a storehouse with uniforms in it on the island. The children don’t wear shoes, which allows their feet to grow strong and tough enough to walk barefoot on the island terrain. The pile of shoes symbolizes the sacrifice that the children make to be part of the group. They give up (for nine years or so) their former lives, which presumably took place in some sort of civilization or family, where they wore shoes and followed customs, rules, and laws dictated by adults. On the island, they follow island customs, some of which are dictated by nature and the physical setting, others by folklore passed down through the “generations” of children. The act of placing one’s shoes on the pile symbolizes the transition from one “world” to the other (the island). The pile itself is seen as a type of shrine, and it’s sacrilegious to dismantle it like Loo does. Even when the shoes’ previous owners depart the island, the shoes stay behind, symbolizing how each child who has lived there continues to be “part” of the island’s chain-like community even once they’re physically gone, having influenced the other kids, the setting, and the island folklore in lasting ways.