be the tip of the iceberg

be the tip of the iceberg

To be only a small, often unrepresentative portion of something much larger or more complex that cannot yet be seen or understood. If Congress doesn't vote to extend the debt limit, a government shutdown will be the tip of the iceberg in terms of what the country will have to deal with. With mobile apps, you have to account for replay value, monetization, ad revenue, and how much the players will spread the game to their friends. Making a fun game is really just the tip of the iceberg!
See also: iceberg, of, tip

be the tip of the ˈiceberg

what you can see of a problem or difficult situation is only one small part of a much larger hidden problem: The 1 000 homeless people in London sleeping in night shelters are only the tip of the iceberg. There are many thousands of homeless people in the capital.
Only 1/7 or 1/8 of an iceberg can be seen above the water.
See also: iceberg, of, tip