Hey Siri, take a selfie. No, selfie!You can ask a Siri to take a selfie, but you can't make it switch the camera...
Some of you will quickly determine this is the dumbest thing you've read on the internet this week. Others will find it so totes important it's ridic. I make no judgements either way. I just call your attention to it: Siri, Apple's virtual personal assistant, as currently implemented, can't take a selfie.
I'll pause while you collect yourself... Okay, onward. You can tell Siri to take a selfie, and Siri will respond by launching the built in Camera app... but that's it. Siri won't switch to the front FaceTime camera. It'll just stay on the rear iSight camera. That's fine for an elsie, but not for a selfie.
The 3D Touch home screen shortcut for "Selfie" on the iPhones 6 can, in fact, launch straight into the FaceTime camera. That makes it seem like it should be possible for Siri to do the same. Since Siri takes the command, it's even fair to assume Siri should do the same.
Since it currently can't, tho...
Source:
Hey Siri, take a selfie. No, selfie!