When a pokemon with tinted lens uses a not very effective move against another pokemon and when a pokemon with the filter ability receives a super effective attack, there is a slight delay between the time the animation hits the foe and when the damage percentage is displayed. That makes your opponent able to tell that you have the ability you're using which may prove problematic in competitive play.
Here are replays :
https://replay.pokemonshowdown.com/gen8customgame-1048546532 ( featuring a filter ninetales )
https://replay.pokemonshowdown.com/gen8customgame-1048544761 ( featuring a tinted lens rotom, with comparison between the "usual" behavior and what I suspect to be a bug )