Here's an excellent story old-school that gives some detail to the event.
It's all pretty routine, given that the second and third test flights were rolled into one, though apparently a little bit of a rush job. For instance, it can carry 13000+ pounds of cargo, but carried less than 2000 (food, "cargo bags", and a few special request science and computer items). And manual docking won't be the norm (I'm guessing). Or will it?
From a certain point of view, though, it's an actual "first", because it's technically crewable, and was risked being docked with the ISS on only its second orbital test. Personally, the fact that the very first flight of the ESA Automatic Transfer Vehicle (named Jules Verne) performed flawlessly in its first ISS automatic docking seems technically more impressive. But safely and effectively rolling tests into living operations is challenging, too.
Can't help but remember, though, that one of the goals is to start carrying people (aka "paying passengers") to "space hotels", of course USA owned and operated - or perhaps "sponsored" would be a better word.
(NAUTILUS = "Non-Atmospheric Universal Transport Intended for Lengthy United States Exploration". Sure! ;)