RJ45 dual LED green and yellow operating
It won't ever turn on. The supply for the chip is 3.3V so the output will be either 0V or 3.3V. It's effectively the same as if the yellow LED die was not present. 

Still better than an eval board I have which has the link LED connected to the power supply through a resistor. You can plug a pencil into the jack and the light still turns on when power is applied.