Costuming for item numbers versus romantic leads
Launch library · evergreen read

Costume choices for a standalone item number typically differ quite deliberately from those used for a film's central romantic leads, favouring bolder colour, more dramatic silhouette and greater freedom of movement, since the sequence exists primarily to deliver spectacle rather than to develop character depth or narrative continuity across the wider story.
Romantic lead costuming, by contrast, tends to track a character's ongoing emotional arc more carefully, evolving gradually across a film in step with the relationship's development, meaning a designer has to think several scenes ahead when planning even a single outfit, always aware of where a character's story is eventually heading.
This distinction gives costume departments a useful creative outlet, since an item number allows a level of visual boldness and experimentation that would feel jarring or inconsistent if applied to a film's more grounded, continuous lead performances, letting a single production showcase genuinely different registers of costuming within one finished film.
Understanding this difference helps explain why an item number costume can look so strikingly different from anything else in the same film, a deliberate creative choice rather than an inconsistency in the production's overall visual approach to costuming, planned carefully from the very earliest stage of development.