Originally Posted by strange_wings
Your iguana looks tense in those pics. Even if your cat isn't going to hurt the lizard it can still cause stress - at the very least for invading her territory. Keep the cat out of the cage, it needs to be a safety zone where the iguana can relax.
If they get along fine outside of the cage - neutral territory, then that's fine, just be careful and watch the body language of both animals to make sure your iguana doesn't get upset.
Petrie's face in the second picture is funny though. It's like he's saying "What?".