A recent entry looked at a commercial system to allow users to look directly at their web cam whilst still being able to see the person they are talking to - Teleprompter style - This is my take on that idea.
It is easy to construct being essentially an upside down periscope such as I used to make when I was a kid.
I have no doubt the commercial system uses better quality mirrors etc. - but this is a lot cheaper . Of course I don't suggest you go into competition with the original manufacturer, in fact this is only posted as a matter of interest to show how these things could work.
Step 1: View of headup display in use
Please note: In these images the lower mirror has been removed. Refer to the drawings to see where it should fit in the lower part of the frame. I also had to put some dark paper over the front of the web cam because it is silver and you could see it through the glass screen.