Lemme ramble for a sec about how much I love subverting expectations you have yourself carefully set up.
To someone who hadn’t been watching this show, seeing that little green curtain go up and reveal this image of a castle wouldn’t really mean anything. It’s a pretty frame, sure, but that’s it. But because every single time we’ve seen this curtain before it revealed the exact same flashback to Utena’s childhood, seeing it reveal something else is kind of shocking. It’s this kind of thing that hits the viewer really hard but is super difficult to explain to someone who isn’t already invested.
My favourite example of this is in Steven Universe, in which over the course of many seasons it was steadily established that all gems of the same type have the same VA; all Rubies are Charlyne Yi, all Amethysts are Michaela Dietz, all Jaspers are Kimberly Brooks, all Pearls are Deedee Magno Hall, etc. And then we meet White Diamond’s Pearl and... she isn’t Deedee. She has a different voice actor-- White Diamond’s VA, in fact, Christine Ebersole-- and because of the way the universe was set up, the way the audience sees a Pearl and expects to hear Deedee, the moment she opens her mouth you know something is very wrong.
Using your own worldbuilding-- or even, as here, your own little conventions-- to throw your audience a little, not to mock or annoy them but to let them know something is different here, something is changing? That’s beautiful.