That's not a pointless warning or anything. Introducing other animals can get the zoo animals extremely irritated. They can go into hunting mode or rampage mode. It's bad enough with just the humans there.

Dogs or pets

Hmm.

apparently cats are exempt from the rule, this one could bring their human.

Griffith Park Zoo is a weird name for a cat.

That’s just a dick move.

There’s good reasons not to bring pets to zoos, it’s not some harmless rule.

Cat looks like she's thinking "Yes, I can read. HE'S the one who's oblivious, but he's also the bigger one with opposable thumbs. So I'm just as aware of the situation as you are. I just can't do anything about it."