Hi, Mick
It seems to be a very interesting feature.
I have not tried it, so I don't know if it will work fine.
I read their page but I didn't quite understand why one should always have the microphone on...and I got a little worried with the possibility of a client being able to save/download the photo somehow (even if right cliking is not enabled).
I think its primary use will possibly be collaborative reviewing (peer review), as you mentioned.
Regards,
-Luiz Muzzi