It is well known that EMI reduction is a problem in PCB circuit design. The braided flat cable pictured is the best conduit for EMI. Thanks for posting.
The terminology can get confusing can't it. Is it "ground" or not "ground". My only thought is that EMI is part of electrical current,EMI can and will travel a path of least resistence and if that pathway is back to ground,I think it's just a matter of semantics. Another point is that those flat braided cables are terminated to the equipments structure(rack) which is tied to ground.Another observation the flat braid cable is his pathway away from the electronics, whether it is in a loop it is still diverts the EMI away from the device. Same principle I use.
I recieved a PM from another member and asked me to define what noise i am talking about. The best audio explanation I could find was this statement from Walter Fields of NBS cable.
"Another source of noise is Electromagnetic Interference (EMI). Whenever electricity, i.e., an audio signal, passes through a wire, it produces inductance that creates an electromagnetic field. Because EMI manifests itself at a high frequency, it is commonly believed not to interfere with the audible range of frequencies. However, all frequencies demonstrate harmonic structures. Even if the cause of EMI is outside the audible range, the upper and lower harmonics of a given frequency often present themselves within the audible range. At the very least, EMI causes degradation of audio frequencies."- Walter Fields NBS Cable
So he was pleased with my answer and in fact he has his equipment rack mounted and star grounded.