Yes, even mailing a package in Bushwick is a little different than in AZ. Robberies are common in this area so the want to protect the mail clerks. In order to prevent someone from getting to a clerk with a weapon the have windows between the clerks and the customers, much like at a movie theater or court house. But people have to mail large packages too, So the have this chamber that you place you packages in. If the clerks side of the chamber is open you can't open your's. But when it's closed and your's is open you can't reach through and open the other side. This is done by a bar that prevents the other door from sliding up while on is open. Anyway, always something new in Brooklyn.
Trying to figure it out, Bryan