All right, that is odd. The two additional red lines might be some sort of visual glitch in the graph, or an idiosyncrasy of the Mac version of Poser.

I loaded a couple of figures and applied Mimic files to each, but didn't get the multiple-line effect in my graph. I only see the line for the currently selected figure, which is how I assume it's supposed to work. I'm using the PC version, with Pro Pack.

I've since discovered that you can also hide the blue waveform visual by clicking the Sound Display button on the bottom of the graph.