The Digital Link Out from the PWR-ICE output is a rebuffered signal of the Digital Input (AES-EBU/SPDIF). 

In other words, it doesn't include any Digital signal processing on the path as it's a copy of the Digital Input. This feature is handy when one wants to send Stereo signal (AES-EBU/SPDIF) digitally between 2 speakers. First speaker grabs the first channel, second speaker grabs the second one.