They did send a couple of extra mirrors along. No mention of what they were or were for.
No mention of what the one with the red cap was either. I had that one on my probe but I will try one of the others to see what happens. It may improve my pictures.
I think the different angles give you a slightly larger or smaller area included in the picture. It won't show up that way in the photo because the micro camera is round and all the area photographed will be shrunk to fit lengthwise. The same scratch or lump might appear longer or shorter depending on which mirror is on the probe.
For our purposes, I doubt if it matters.