In a very upscale "tract home" I found only a handful of actual code violations. This is one of them.
Taken before the flooring was installed, the single receptacle was mounted in a standard flanged plastic box. While it may resemble some "real" floor boxes, it lacks any means to adjust for flooring thickness. (I will try to get a pic when the finished floor is in place).
Also lacking will be the heavy-duty coverplate. I doubt the "standard" type will stand up to...being stood on(!).
John, Is that a "showcase" outlet? It looks like one I have from P&S, It comes with a brass plate and a screw in fitting to cover the socket itself. It's listed in their catalog under "floor boxes" also...