Very good translation job. A little bit of correction here:

>The first means the picture are from Chinese city.

The first sub-forum or sub-board, actually means "Original Artwork", photos taken by the poster, either a posed session or snapshots from the street(also those posts with the owner's authroization, and in the owner's name). So by contrast, second board is for any long hair photos NOT taken by the poster personally. No adult contents allowed, minimum requrement is a "bikini", and has to show hair more prominently(otherwise it'd be relegated to the "Watery board", where anything NON-hair related, and in good taste, goes. A "water post", as we call it. I'm also the mod on that board.)...