i think they mean the fact OS4 is theoretically sold in a cardboard box with a manual. OS3.9 was only ever a CD, but I remember OS3.5 came in a box, with a (thin) manual.
OS3.9 had only a jewel case with a booklet and an option of a heavy book, thats right but due to the fact that the cardbox of OS4 was send as DIY Kit to most of the customers and not build or wrapped like the OS3.5 box I wouldn't call this a professional production either.