I stayed up late last night scanning pics from "Nach Baliye," and this morning they're all corrupted! Can't open any of them. &*%^@! But then I realized that since Pooja mentioned it first, she technically owns the rights to this topic!
In the beloved Bunty aur Babli (which is my new "intro" loaner to newbies, since it is impossible not to like it...) I have long watched "Nach Baliye" and asked, "what were they thinking?!" Rani's costumes for this number are so appallingly ill-suited to her figure, especially in contrast with the variations worn by the backup girls.
So I suspect that someone lost a bet... or, bet someone that they could get away with dressing Rani in a dreadful wardrobe for an entire song. This, despite the wonderful fitted Salwar suits & various costumes she wore throughout the film.