I think it says that no animals were mistreated? And it appears on pretty much all American films. Just verifying that no animals were used at all fulfils that.I think they did a bit of practical stuff -- there's a Humane Society certification near the end of the credits saying they monitored how animals were handled in the movie and that they were all treated well.
I remember RTD saying in a recentish Doctor Who behind the scenes thing that they had to put that notice on the Disney+ episode releases, but it's not on the BBC versions. As he said--they didn't use any animals at all, but still had to have the stamp verifying that they didn't harm any.