I started doing a course on coursera.org and I noticed the lecturer was using a clear whiteboard in front of the camera which enabled him to draw on the whiteboard while facing the students. It was very good so I searched for glass whiteboard and discovered it’s called a “lightboard” which is a glass whiteboard with LED lights around the sides. It was invented by Michael Peshkin from Midwestern University. Here he is explaining how it works:
In this new era of online learning the lightboard is a godsend. If you’ve got the skills you can build one yourself for less than $100. I also found a UK supplier that sells them for £819 but they’ve sold out.
rachel.blog 
I thought this was going to be like when I was at Uni and two of the tech type undergrads were building a computer in their spare time but it’s more DIY than that. £819 sounds quite steep. I suppose it is very specialist equipment, although I think I have seen similar in crime dramas on TV
It’s really just a glass board with LED lighting around the sides so I don’t think it’s that specialist. It’s probably just expensive because it’s still quite new and there’s not yet much available on the market. I see the site I found selling them is still out of stock.