 Most of the island scenes were filmed from April 9 , 2007 to April 12 . A detailed episode synopsis was uploaded online before the episode aired and Disney investigated the leak . The name of the Dharma station in the episode is an allusion to Lewis Carroll 's novel Through the Looking @-@ Glass . Dominic Monaghan was inspired by Leonardo DiCaprio 's underwater performance in Titanic and opened his mouth briefly underwater to appear under greater duress . 
