It would be really interesting to read more about the physical participants' impressions of this. Having a screen on a stick with a live human face on it follow you around must be quite the uncanny valley.
The people I worked with had a lot of fun with it. They'd dress it up like me, prank me by putting things in the way I couldn't see, etc. Occasionally they'd lose their composure at talking to it and start chuckling, the uncanny valley you mention at work I suppose.
I would probably find it rather creepy, because all it reminds me of is some dystopian sci-fi: