This came up at the start of a double battle. Did I do something wrong? What does this mean?
No you're not doing anything wrong.
This message can come up in battle when a Pokémon is sent out and has +2 Affection.
Hope I helped :)
This just means you've played with Talonflame on Pokemon Amie. It's actually good, despite the negative context. xD
Hope I helped. :)