Rewarding the user for wondering and trying
There is also something great in seeing an interface that grows with you, or one where you can say “I wonder if…” based on your prior interactions and expectations, and the interface actually rewarding you for that thought.
I can get pretty strict about the use of terms, symbols, and gestures in an app. This kind of discovery of features is what that kind of strictness and consistency allows for. I see it very similar to game design, where you teach the user the rules of your interactions and visual vocabulary, and once they’re in that world they know what to expect.