Just in the way that 'Adam and Eve' as Locke called them, were positioned in the cave. Implied they loved each other as they were lying side by side (Question remains did they die at the same time? Or were they placed there?). There was also the bag, which contained two small, smooth (polished?) stones, one black, one white.
Here we have Bernard and Rose. Bernard is using black rocks to form an S.O.S. signal. (Aside from the obvious, Rose is black, Bernard is white).
Rose is healed by the island and even if rescue boats come, she says she won't leave and Bernard makes the decision to stay too.... Does anyone suppose that 'Adam and Eve' elected to stay on the island?
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I also think that with the food drop, the Lostaways are now forced to accept that someone knows that people are on the island, and tho they provide food, they're all right with people dying while being forced to participate in their experiment.
Up to this point, it's been possible that a plane or boat might pass; this was a revelation that there's some entity that wants to keep them there and can probably block any attempts by rescuers. If they want to get off the island, it's going to have to be at their own intitiative, not Dharma's.