The phrase "getting to the bottom of it" very well illustrates the meaning of the Iceberg Model. You need to dig deeper to understand the situation and see the whole picture. The analogy is simple - you can see only about 10% of the iceberg's surface, its tip. The bigger part is hidden and it's your choice whether to make an effort and explore it or satisfy yourself only with the "visible" part of the information. This model applies to almost any life situation you might experience.
The first thing you can see is the event itself. The only thing you can do at this point is to react. For example, you see that a person can't breathe. You can react in several ways. You can do the Heimlich maneuver if you think that it was food that triggered this reaction or give that person mouth-to-mouth. You don't know the reason so you can take a wild guess and act immediately. If you are wrong, it can lead to the disappointing consequences.
Alternatively, if you choose to analyze trends and patterns, ask others some questions, the situation will look clearer. That person might have a disease you don't know about and none of the methods we've discussed here will be helpful. Once you analyze that, you can respond to the new input. Note that a good doctor will not try to cure a symptom, she will try to find the reason for that symptom to appear. The deeper you dig the better.