How do I fix my bathroom mirror

You're not supposed to actually fix it.

The point of the broken mirror is it adds a bit of depth to your character - he keeps breaking it because he can't stand to look at himself.

Adam broke the mirror because looking in it reminds him of his augmentations, and looking at his augmentations reminds him of his failure to protect Megan. He is not going to fix it.

It has absolutely nothing to do with Eidos Montreal deciding not to program in any reflective surfaces and the complexities therein. ;)

You cannot fix the mirror, it simply adds a story element to the game.

Screenshots of the emails for anyone interested:

Email on Jensen's computer: http://i.imgur.com/A1JuD.jpg

Email on lobby computer: http://i.imgur.com/Fsk2Q.jpg

Mirror with note: http://i.imgur.com/lerp9.jpg

Out of story reason:

Showing a mirror in an FPS requires an extremely high quality of animation for the main character to avoid brekaing immersion; these are animations that normally would never be visible in first person. As such, the dev cost of including a mirror is very high relative to rare occurrences. This is why the mirror is not reflective, even though it's a mirror.

Not only that, the frequent broken and missing mirrors in the game call back to the orignal DX, which featured really terrible mirrors (unsynced images, bad animation). By breaking all the mirrors they could avoid the same thing happening again