This was a project that tinkerers and makers really ran with. My favourite was using CDs as the reflective surface and a taped pencil as the stand:
Some had adjustable hinges to fit different thicknesses of monitors and laptops. Careful measuring of thickness would allow makers to create different models for distribution.
For more info and suggestions take a look here.
For my school, I opted to make one universal-fit model. We are a BYOD school so there are dozens of computer types and thicknesses. I also needed it cheap and quick and easy to produce since I wanted students to take them home in case they need them should we go virtual.
Ours ended up being about 2 grams of 3D-printed PLA plastic (2 cents), a 1" square mirror sourced from Amazon (13 cents), and a clothespin (7 cents). For about $66 I've been able to produce enough for 300 students and teachers!