They're nicknames. It's hard to explain.

[ He spilled wasabi on his shirt one time. Fred focused on weird details. Hiro wasn't sure he wanted to know what his eventual nickname would be. ]

I've never heard of your model of robot. [ He peers in close to the screen. He was well programmed to have that sort of tonal variation in his vocal processor. Plus the personal gestures... ]

What's your functionality aimed toward?