(i) The quartermaster of an interstellar spaceship:
feeds the gods with rabbits because there is not enough room for cattle on the ship;
asks the Cardinal Archbishop of New York the names of the top local gods because it would be a good idea to kill some cattle for them to avoid bad luck;
but otherwise is more interested in discussing what is on television.
The Galactics had not understood the Cardinal's request to meet their chaplain not because of any linguistic problem but because they need no word for "chaplain" other than "quartermaster, when he is feeding the gods." Imagine if that was the highest level of religion that was ever to be attained.
(ii) When the vibrations generated by a star drive are detected emanating from a new planetary system, a mission is sent to check whether the new interstellar travelers still wage war among themselves and, if so, to destroy every planet in their system. That is what would have happened to the entire Solar System if a star drive had been tested while wars were still waged on Earth.
Imagine if that was the highest level of morality that was ever to be attained.
(iii) The concluding sentence of the story underlines the Galactics' backwardness when a con man, having befriended the Federation emissaries, sells them the Brooklyn Bridge. This is short-sighted but, because it happens at the end of a short story, we maybe smile, then stop thinking about it. The public had been warned not to harm the powerful Galactics as they shop in New York. In fact, the Galactics are protected by an invisible force screen but not all harm is physical.
Apart from being a lousy trick to play on a bunch of guys after befriending them, what will the confidence trick, when it is inevitably discovered, do to interstellar relations? Anderson could have written a lot more about the diplomatic repercussions of the Galactics' arrival.