The OWC Mercury is currently only offered for sale at the company's web store, so there wasn't a need to hit the market with a full retail package.
Here we see the white box-like solution. Maybe Mac products actually get a black box and not white? Either way, the concept is the same. OWC does label the package over the opening seam to keep the package securely closed.
On the inside we see that the drive is sandwiched between two pieces of foam with the drive itself wrapped in an antistatic bag.