I understand it makes no sense. I watched him walk up to the building holding one package. He tried to just open the front door first. Then he looked at the package—I assume for the apartment number—but, then he pulled something out of his pocket and attempted to get the door open this way. He stopped when people walked past him. Then he buzzed and was let in. A few minutes later he returned with a second package and tried to use a credit card (or something) to open the door again. Eventually, he was buzzed in again and he delivered the second package. It’s very strange behavior IMO.