Um I guess
Only if you take the mirror and grind it up into very fine particles, so that you get diffuse (as opposed to specular) reflection.
If you leave the mirror intact, it will of course not appear white, unless it happens to be reflecting a white object.
Yea, sometimes I just use a sheet of paper, as a mirror, to shave.
And it be more white. Everytime a Gora stands before it 👀