The example of an iceberg shows the need to see under people’s surface behaviour; the need of a deeper insight.
Only 10% of an iceberg is visible on the surface, 90% is under the waterline, invisible, but yet prominent. If there is a wind coming from left to right, just by seeing the visible mass, we think it will move the iceberg to towards the right. If, against all expectations, the iceberg moves in the opposite direction (left), it is because, under the waterline, there is a strong current running towards the left.
Sometimes you, as a leader, try to move people in a certain direction by giving them orders, instructions, explanations and encouragement, but you do it on the basis of what you see above the surface. The visible part represents what is at the surface such as appearance, behaviour, manners etc. You do not see what moves them under the surface so you become surprised and maybe frustrated seeing them move in the opposite direction. The main part, which is the 90% not visible, is within the subconscious. Under the surface (subconscious) you will find emotions, fears, attitudes, deeply held values etc.
If you want to move people, if you want to motivate others for a project or even just to reach others, you need to be aware of these kinds of things that you find under the surface. The key to understanding others better is to be more aware of your own feelings and under-currents, because, at a deep level, we are very much alike. If you understand your own fears and strong motivators, you will understand others much better.