"Meet the team" allows existing people in the department to get a feel for your personality, and make an initial judgement if they'd want to be on the road with you for an extended trip.
For a 91 department, this step of the process is vitally important to recruit the "right" people, ie. pilots that will fit into the department's culture and personality.
In such a situation I'd simply be myself, while maintaining SA about where I was (ie. be mindful of language and comments, don't become TOO casual/comfortable, etc.).
Try to not overthink it too much, just be as relaxed as possible and get to know the other people in the department.
Remember, you are interviewing the department just as much as the department is interviewing you...