In Star Wars lore, the Mon Calamari and the Quarrens are from the same planet, and the two species have an ancient and permanent rivalry with one another.
The droid bar features many Easter eggs, with a range of recognizable droids. Attentive viewers will spot protocol droids, astromechs, battle droids, gonk droids, pilot droids from the original Star Tours ride, even the chef droid first seen in Star Wars: Episode II - Attack of the Clones (2002).
Director Bryce Dallas Howard's husband Seth Gabel provided the voice of the droid bartender.
Robots at the droid bar are boozing on Nepenthe - a reference to Homer's Odyssey, in which Helen of Troy (the very beautiful daughter of Zeus) creates the drink by doping wine with a drug "to quiet all pain & strife, and bring forgetfulness of every ill."
In the droid bar scene, there is an appearance of the pilot droid, Rex, from the original Star Tours ride that was at Disneyland and Disney's Hollywood Studios. In the version of the ride as of release, you can see the droid in a shipping container as you walk through the ride's queue.