Oh I finally get it now. The costume's that Pikachu is wearing represent the 5 types of contests that you can enter in game.
>Madame Pikachu - Beauty
>Hard-rock Pikachu - Cool
>Idol Pikachu - Cute
>Doctor Pikachu - Smart
>Masked Pikachu - Tough

So contests are pretty much confirmed then?
I'm actually pretty excited to see how they implement this feature and how the contests will work now. This seems like a very interesting concept.