There is no actual "white elephant" in the story. The title "Hills like White Elephants" is a clue to the meaning of the story. A white elephant is something that you have that you really don't want. Years ago, and even today, people have "white elephant" parties where everyone brings something they already have but don't really want ( like some ugly ceramic statue of an elephant). They wrap it up and then exchange the "present" with someone else. Sometimes you get something you want and sometimes another white elephant. Anyway, the child that the man wants to abort is the white elephant in this story. When Jem says "the hills look like white elephants" she is alluding to two things. First, her partner is trying to convince her to have an abortion to get rid of a baby he does not want. Also, if you think of an elephant on its back, its large stomach can remind you of a pregnant woman. Since Hemingway is using language very sparingly in the story, this is his way of saying that the man does not want Jem to be pregnant.