- the neutral arbiter of the rules, enforcing them as best you can, rather like an umpire in a baseball game?
- the advocate for the cause, like the Army Chief of Staff for the army?
- the helpful postal clerk, who attempts to guide the aged customer with an odd package through his options?
- the social worker, encouraging the client to do the right thing?
- the FBI agent, enforcing the law?
There's also the question of different personalities: some people are effusive and outgoing, others (the better ones I say with total bias) are reserved and taciturn.
It's often difficult to judge a bureaucrat's behavior fairly without seeing a lot of their interactions with clients/customers.