I hate the stock images on the front page. Should these be webcam video streams?
My initial reaction was that they were profile images representing the people involved in the chat. I have a hunch that "normal" people will think the same.
Otherwise, the product looks very interesting, looking forward to having an opportunity to try it out.
The issue isn't so much that they're stock images per se - more that they don't give me an idea of what the product actually looks like in use.
Also, if possible have the photos set up so the person is facing towards the action you want them to take - the get a meeting room button. Anyways, just a tip, I think it looks very clean overall. And, just went to a meeting room and the onboarding is great. I was in a meeting room within 10 seconds - very nice.