In your example, the "come up with your own story" part is the creative part. But you're not "directing" the AI to generate it for you. You're just giving it a command. You're selecting from the results it outputs, but you're not controlling the output.
A film director is a creative. Ultimately, they are in charge of "visualizing" a screenplay": the setting, the the design of the set or the utilization of real locations, the staging of the actors within a scene, the "direction" of the actors (i.e., how they should act out dialog or a scene, lighting, the cinematography, the use of stunts, staging shots to accommodate the use of VFX, the editing (meaning, the actual footage that comprises the movie).
There's an old show on HBO, Project Greenlight, that demonstrates what a director does. They give 2 directors the same screenplay and budget and they make competing movies. The competing movies are always completely different...even though they scripts are the same. (In the most extreme example from one of the later seasons, one of the movies was a teen grossout comedy, and the competing movie was some sort of adult melodrama.)