Several times during the film, Precious looks in a mirror and sees who she aspires to be (in a literal manner; someone else is shown in the mirror every time, usually a Caucasian girl with long, blond hair). In a narration near the end, while we see Precious looking in a mirror again, Precious says that Ms. Rain told her that she is beautiful as she is. Precious then says "As crazy as it sounds...I think she's right." We then see what she sees in the mirror...herself.
When Precious breaks down in tears after her mother throws her out and says that nobody loves her, Mrs. Weiss tells her that peoplde do love her. After Precious tells her about how her parents' "love" for her caused her to be unhappy and to feel worthless, Mrs. Weiss reassures Precious that that wasn't real love and that she loves her.