Everything is relative and everything is a tradeoff, so I think what they are trying to say with ultra-low latency is that they have tried to minimise possible

Everything is relative and everything is a tradeoff, so I think what they are trying to say with ultra-low latency is that they have tried to minimise possible sources of latency and that make all possible trade-offs to favour lower latency. A streaming music service might for instance buffer audio (which incurs latency) to get reliability, which FarPlay probably doesn't do