>>58816363There's quite a few reasons for Cosplay Pikachu and her five costume Forms. One major one being to promote the return of Pokémon Contests in ORAS. Each of her costume Forms represents one of the five categories.
In order from left to right as shown in that image:
Pikachu, Ph.D. represents Clever
Pikachu Belle represents Beautiful
Pikachu Rock Star represents Cool
Pikachu Pop Star represents Cute
Pikachu Libre represents Tough
She even gets a Move for each and starts out already with some Contest Stats, along with just being given to you, can be used as quick easy choice for Pokémon Contests while being yet more special treatment for Pikachu.
