In S02E09 of The Marvelous Mrs. Maisel, there's a scene where Joel proposes to Miriam at a diner and they dance in the streets, after she says yes, blocking oncoming traffic. The scene cuts to Miriam waking up in her bed and walking over to find her new boyfriend being interviewed by her father before he could propose to Miriam.
Was that scene with Joel and Miriam a flashback or a dream sequence? I had doubt because Miriam, who's a natural brunette, had blond hair in that scene. So I thought it was a dream as she wakes up right after.