Review (4/5): Definitely NOT Fogless, BUT...
As other reviewers have noted, this mirror is not even a little bit close to fog-proof; the entire thing fogs up as soon as the water in my shower gets remotely warm.
However, as others have suggested, this problem can be easily solved with a handful of soap or, in my case, non-foaming facial cleanser. Just wipe some onto the mirror, rinse, and it'll be fog-free for the duration of your shower.
I love everything else about this mirror. The design is minimalistic and sleek, the mirror itself is shatter-proof, and the adhesive (which isn't an adhesive at all, just part of the silicone covering the mirror) works really well! Thing's stuck on my wall like glue! Just be sure to follow the instructions as it can be a little tricky to get it to to stick just right the first time around.