That's how picking works in C3. The parent "On tween" event picks a single instance of pam_paws for the entire event.
If you want to access other instances in the same event, you need to use "Pick all" condition - but it will only be active within its sub-event. Once the sub-event has finished, the picked scope reverts to that single instance.
The order of conditions is also important. In this case "Pick all" needs to be first, above the "compare instance variable" condition.