Just the second entry to feature Mary Ann, this one is marginally better than The Postman Cometh. It's undermined by a stock premise that would make more sense back in the first year. Still, an episode where Mary Ann and Ginger swap roles for a day can't help but be fun, entertaining, and feature a lot of outfits.
Glamorous Ginger performs for her appreciative audience in the cold open. Mary Ann is particularly awestruck. She trips over a rock during the curtain call and conks her head. Instead of being concussed, she awakens thinking she is the movie star.
The Professor diagnoses her as having a bad case of Ginger envy. He suggests humoring her to prevent any kind of psychological trauma. So we have that old sitcom routine where the girls change places. Mary Ann clearly gets the better end of the deal; she gets to wear a slinky leopard-print number and rehearse a love scene with a reluctant Gilligan. Ginger, meanwhile, adopts the farm girl's trademark pigtails and checker board outfit. Ironically, the accomplished actress is never convincing as Mary Ann and does nothing memorable with the role. She gets so tired of the act, in fact, that she takes off her wig to do the laundry and gets caught by her double, who faints straightaway.
Despite the shock of 'seeing herself,' Mary Ann awakens still thinking she's Ginger. The Professor borrows the hypnosis bit from the first season episode Forget Me Not. Somehow, just like that earlier attempt, his hypnotic suggestion bounces off her and hits an eavesdropping Gilligan.
With the original plot point having ground to a standstill, there is time for a detour with Gilligan now as Mary Ann. The scene may be padding, but, to be fair, it is very entertaining. Writer Don Friedman gets as much mileage out of Gilligan's bashful act as he can. This bit and the Professor's reverse suggestion that gets our lead back to normal work really well.
With that fluff out of the way, the episode returns to the problem of what to do with the new Ginger. The Professor's solution is so simple it should've come to him earlier. Anyway, Mary Ann's big musical number is both painful to watch and hear. It is the last time she takes center stage in the series.
COCONOTES:
Ginger, whose character is based on Marilyn Monroe, sings "I Wanna Be Loved by You," sung by Monroe in Some Like It Hot.
Major, major plot hole: We're expected to believe that Mary Ann, living with Ginger for nearly 3 years, wakes up one morning and realizes her hut mate is a movie star and wants to be just like her.
Using those loud, screeching notes for Mary Ann's second smooch with Gilligan is insulting and over-the-top.
That's Dawn Wells' actual singing voice at the end.
All of Ginger's dresses are miraculously restored by the next episode.
Gilligan does admittedly look cute in the epilogue.