(2 coats)
You could get opacity from 1 coat but I have learned that my ideal number of coats for minimal chipping and peeling is 2 coats so I always try to keep it to 2 these days. (Be warned: one coat or 2, this is a chippy SOB.)
(Millennium is on the left, Mirror Image on the right)
I remember when I first really launched into my nail polish fancy, minx was everywhere and I was obsessed with getting that look. At the time, the closest way to replicate it with a polish was Maybelline's Mirror Image, which I paid through the nose for on eBay (the only time I've done that).
As you can see they are basically identical. In person, the Mirror Image is ever so slightly more mirror-y. Very slightly.
I'd still go with the Millennium, however: (1) Mirror Image wears incredibly strangely; the elements to weird things to it. It's not durable in the slightest. (2) You have to use that glue base-coat it comes with. Why go to all the trouble. (3) The bottle Mirror Image comes in is SO small, it's basically a mini.
