It can be either. If you set it to 0 it will immediately detect the blinking, but if you increase the detection delay, you can adjust so it looks for a change when the light is off, thus it doesn’t detect blinking. Mine is set to 4 seconds. You Have to do some experimentation to get it right for your machine and the cadence at which the light blinks.
There’s also a no detection setting, but I think it didn’t work for me can’t remember to be honest, but I know that my setup works as I expect it to and doesn’t detect blinking.