They cut some of Siri’s responses when unnecessary. No “Calling so-and-so, iPhone” or similar.
They didn’t use Siri’s new iOS 11 voice; a missed opportunity to showcase it. It’s a shame, because Siri sounds a whole lot better in iOS 11, although it’s a little stunning at first since she sounds like a different ‘person’.
Voice is the newest mainstream input method for computing, and is far from perfect.
If Siri worked this perfectly every time, more people would be inclined to use it. I think Apple is painting a picture here of the possibilities and use cases Siri offers—not that anyone didn’t know a majority of the commands, but it serves as a reminder in a sense of “oh yeah, I can try Siri for that”. My advice: use Siri as much as you can, so when its eventual accuracy improves, you’ll be a step ahead.