That doesn't mean "polished" like silver; It means it was sanded down with very fine grain sandpaper, for a smoother texture.
Some claim that polishing will make a more nonstick surface. Others claim that polishing hinders the seasoning process, since the seasoning will have nothing to grab onto.
Polished cast iron is very hard to find, and probably expensive. So I won't be trying it out for myself any time soon, in order to give my own review.
You can try polishing it yourself, using 220 grain sandpaper. But I'm not going to.
Rumor has it that Lodge discontinued their polished skillets because the machine broke and it was too expensive to fix.
Lodge maintains that it was due to lack of consumer interest.