Mellisa is teaching other girls how to work at nursery as part of a course. She want to teach these girls how to change diapers, feed a baby, dress them and so forth.  However, she cannot use real babies since these girls haven't been trained yet. That's where you come in: You've been hired to be a "baby" so these girls can learn how to take care of real babies. Mellisa will give you clear instructions on what to do and expects you to make the demonstration as realistic as possible. 