Does the meaning of the hills change as the story progresses?

At the beginning of the story, as the couple waits for a train while sitting at the bar, Jig remarks that the hills in the distance "look like white elephants." She seems to be attempting to make casual conversation with the American. He is, however, a bit testy and irritably replies to her comments. When she suggests that he wouldn't have ever seen a white elephant, he responds, "I might have . . . Just because you say I wouldn't have doesn't prove anything." After a bit of banter about drinks and drinking (typical of a Hemingway story), the true meaning of the white elephant becomes apparent.
A white elephant is a burdensome gift. Legend says that the King of Siam would give albino elephants as a gift to his enemies with the expectation that the upkeep of such a beast would be a serious inconvenience for the recipient. In Hemingway's story the white elephant is the unborn baby which Jig carries. The man argues that she should have an abortion ("just to let the air in"), which she clearly rejects. Thus the hills change from being a simple element of the setting to a metaphor for what the American clearly believes to be something unwanted in the couple's relationship.