Siri has her moments. And from time to time, she starts cracking jokes. While not all of them are funny, it gets better when she starts trashing her competitors.
Siri got an update that taught her the difference between "glass" and "Glass". When you prompt her with Google Glass activation phrase ("Okay Glass"), expect her to fire back with some attitude.
Its not a glitch either. She's got several different responses to the prompt. Check it out. [The Verge