I also considered putting a smallish blood stain on the front as if the alien were in the process of busting out.
Other suggestions I liked were:
a wolf of some kind because she is reminiscent of Little Red Riding Hood.
a bottle of vodka because of the Russian nesting doll thing.
a little demon and that would go along the same lines of the alien.
In each case I think I would alter the facial expression to match the inner item; drunk if it were the bottle of vodka, scared if it were the demon or the wolf.