I don't get Pikachu's appeal at all.
Also I'm guessing each costume is for a different contest type. Madame for beauty, hard rock for cool, doctor for smart, idol for cute and wrestler for tough. Also they all seem to have the same weird black-heart tail so it might just be another special pikachu like that spiky eared one.
I'm sure this will only be for Pikachu but I would've really liked it if they allowed clothing options on all Pokemon somehow, that'd actually be kinda cool.