Use Fix-it-All adhesive to glue your new frame directly to the underlying mirror. Allow it to dry overnight, then attach some Command strips on the back to hang the mirror on the wall. This fun ...
It appears there is more than one way to hack a mirror, or anything, which is what makes hacking fun. [squix] started with a picture frame, adding tinting film to the glass so it would reflect.
Bathrooms are notorious for collecting clutter, but with this simple project, you can create storage without making permanent changes to the room's structure.