If so, can I see some pictures? I want to know if it could be shiny, or could at least see what it's shiny form looks like in each costume :)
No, there isn't a Shiny Cosplay Pikachu. Cosplay Pikachu is Shiny locked, unfortunately.
Cosplay Pikachu is different from normal Pikachu, therefore it is shiny locked. It cannot breed either, and can learn special moves which regular Pikachus can't