Explanation:

There are some persons like me who are strict on controlling things around them, who sometimes doesn't think the effects on to others.(me? sometimes only!! xD) The feeling that you are not satisfied if you don't have the control on something that you think not in place like (money, feelings, emotion, friends, attention, etc...).

As for the wallie. The girl (my classmate) is holding the earth indicates that she is also strict on controlling things around her, that she wanted to put in the place where she thinks the right one.