Big-Lipped Alligator Moment: Kokone has a job as a delivery person. While out on her rounds one day, she pulls a gun on someone who startles her. This the first indication we have had that the setting in general and delivery work in particular is dangerous enough to require armed protection, and the gun (a Static Stun Gun, by the way) is never mentioned again. The closest we come to violence in the entire series is a woman saying hurtful things to her romantic rival.
Fridge Brilliance: Alpha's owner sends her a present together with a coded message which needs to be delivered by a robot. In hindsight, this is obviously a ploy to make Alpha meet other androids, make new friends and come out of her isolation.