I guess I'm getting the exact opposite from it. Instead of offering transparency or mirroring effects in the astral, they just impair vision. So you're not going to see that aura reflected in the mirror's astral shadow, because it's just a grey blob.
I guess the reason I see it this way is because they combined "transparent or mirrored" into the same clause. There is no reason I should be able to see through my bathroom mirror, but not the just as normally opaque wall beside it. Instead it just impairs vision just like every other astral shadow. Transparent objects are, by the same clause, in the same shadow.