It all comes to quality of electrons. With music AC signal they simply eagerly oscillate, as Rodman99999 stated. Unfortunately with a little bit of DC present, they slowly drift toward the end of the cable (drift velocity) and "poof" they are gone. Your expensive electrons just got replaced by lazy generic variety :)
How does cable construction affect sonic character?
I think this altered cartoon expresses the gap between cable skeptics and believers. No one knows what happens in the brain, the machinery between the engineered cable and the subjective experience (expressed in language). It's something miraculous -- or, for skeptics -- it's nothing.