Red Light below Driver's Side vent

Hi all,

I recently bought a used 2007 Corolla CE and noticed that there was a small red LED light right below the drivers side air vent (see picture below). I've never seen this light in other pictures of a 2007 Corolla, and it was also missing in a 2008 Corolla CE that I owned in the past. Does anyone know the function of this light? I'm very curious.. Thanks