This is basically a fluff piece inserted into the conversation that worries about the machine bias, the ability for it to do stuff like figure out race by proxy, and possibly use that knowledge to learn biases assumed to be present in its training data.

To be honest, the network can always be run in reverse. If it lights up a "black" label, or whatever, you can ask it to project back to the regions in image which contributed most to that label. That is the part it is looking, in some very real sense. I guess they did that and it lighted up big part of the input, so it is something like diffuse property that nevertheless is systematic enough for the AI to figure out.

Or maybe they didn't know they could do this and just randomly stabbed around in the dark. Who knows. As I said, this is fluff piece that doesn't tell you anything about what these researches were actually doing except doing some image oversaturation tricks, and when that didn't make a dent in machine's ability to identify race, they were apparently flummoxed.