The "shiny mark" happens regularly when a shiny Pokemon comes out of it's Pokeball. As for the "Pink Pokeball" I don't know what it is. If you are talking about this -> , then that is the Pokerus cured sign, but it doesn't appear when a Pokemon is sent out to battle, it appears in the Pokemon's summary. If you are talking about this -> being the shiny mark you are talking about the Pokemon's summary.
EDIT:
If your Gardevoir has beaten Master Rank for all five Contest Spectacular types, when you send it out to battle, a pink ribbon will appear when it comes out of it's Pokeball.
>If you manage to win Master Rank Contest in all five types with a single Pokémon, then it's very special. This Pokémon will get given a special ribbon known as the Contest Star Ribon.
But that's not all. When you send this Pokémon out into battle afterwards, it has got a special animation which shows a shine and a faint ribbon over it, proving that it truly is a Contest Star.
Hopefully that explains it better than I can.
Also, some of the credit for this answer goes to SapphireDiancie for reminding me about the pink ribbon.
Hope I helped!
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