An iceberg is a large piece of freshwater ice that has broken off a glacier or an ice shelf and is floating freely in open water. The iceberg symbolizes fear of one's own feelings, and that one needs to take control of them.
The Iceberg Principle, or Iceberg Theory, is a theory that suggests that we cannot see or detect most of a situation's data. A theory that suggests aggregated data can hide information that is important for the proper evaluation of a situation. Therefore, to gain control of one's own self, a full understanding of the entire situation is required through exposure and in-depth analysis of all of the data.