Click through the gateway link. Notice the direction of the Arrows. Your high level code is still directly dependent on the current low level implementation. The "Gateway pattern" is nothing more than create an abstraction so your code can work with domain concepts instead of directly with the API.

Now look at the arrows in the DIP example. There is an inverted arrow by comparison to the gateway diagram. This is because you have inverted the dependency so that your high level code no longer depends directly on the implementation.