No, this isn't a polish. Yes, they are fake nails.
If you remember, I tried one of these fake "mirror nails" on the other day and compared them to other mirror-like finishes. These are actually a different brand than the one featured in that post.
Nail Bliss - Silver Chrome Nails
These are the same nails that Scrangie reviewed in her post here (although hers were the "Platinum" color, and these are the "Silver"). They are a bit thick, and don't look too incredibly natural (they're a little too wide), but I love them all the same. I also had the same problem I have with most fake nails which is that most of the sizes are too large, so I have to use the smallest sizes available and hope they look ok. Because Scrangie remarked that the chrome finish was easily scratched, I decided to put a layer of my SensatioNail UV gel top coat over them to protect the finish and keep it nicer longer.
I attached these with Elegant Touch Super Adhesive Tabs because I didn't want to fuss with nail glue but still wanted them to stay on for a few days while I'm on vacation. I'll comment on the wear after I have them on for at least a couple days.
The nails featured in this post are here on this site, though not available for purchase. I found mine at Sally's, though I looked for them recently in the local store and didn't find them.
At Ulta I was able to find a similar brand (that actually fit my nails even better) called Elegant Touch. The metallic ones I found can be ordered from their site here. They are a little closer to the "Platinum" color of the Nail Bliss nails (the color in Scrangie's post).