When doing battle at a gym, messages appear next to both your Pokemon and the enemy Pokemon. Some messages are obvious, like "Dodged" appears above your Pokemon when you successfully dodge.
What is not so clear (at least to me) is when a message like "Not Very Effective" appears above my Pokemon, does that mean my Pokemon's attack was not very effective? Or the attack that is hitting my Pokemon is not very effective?
Whatever the answer to that is, I assume it applies to the messages above the enemy Pokemon in a complementary fashion?
Best Answer
It means the attack hitting your Pokemon is not very effective. As you suggested when it's complementary, when you launch a not very effective attack, it appears above enemy pokemon.
as you can see here kadabra's psychic attack is super effective against nidoran as she's a poison type pokemon.