Yes, I believe Austin is right. From this platform weighted lines/ropes are thrown to the shore-side workers when berthing. I believe there is usually an Officer on each platform, who is in continuous contact with the bridge. Passengers are obviously not permitted in such areas of the ship for health and safety reasons - ropes are checked & maintained here, and can kill people when not handled correctly. The image below shows somebody throwing a weighted rope from one of these platforms:
http://www.oceanopportunities.com/images/pictures/study_indexpic_14.jpg
James