I used to do tech for a large company- every once in a while someone would bring in a laptop for repair, and there'd be a piece of tape over the ambient light sensor.
I don't embarrass my users if I can help it, but I do ask why the sensor is covered up. :-)
Maybe because the ambient light adjustment is annoying and covering the sensor is a fast/easy way to “disable” it.
I watch the lens being covered up on the display while I cover it.