The main purpose of the light sensor is to detect a wave gesture in front of the device.
The way this is done is that an IR-light is transmitted from the device and captured by the light sensor, and if you break the path of that light with your hand or another object, that indicates a wave gesture.
The placement of the sensor in the device is designed for this purpose, so the sensor is not very exposed to light in general, and it does not have a cosine receptor to capture light from all angles.
However, we have found that it could be beneficial for some customers to see the amount of light captured by the sensor to determine if lights are on in the office at night or similar things, so we filtered out the IR-light and presented the visible light captured as a percentage in the Dashboard.
While it does capture lux levels, it is not possible to know the actual value because it depends on the orientation of the device and the light source placement.
This is why we can't present the light levels in any other way than a relative percentage of what we can measure with the sensor.