Can't do it by line,you have to do it on a ship by ship basis and in some cases on a location on each ship basis. Example , many balconies on Grand Princess are not private from above, while Sea
Ocean and Dawn most balconies are private side to side and from above. What ships in particular did you have in mind and what catagory of balconey on that ship? By the way, these are questions you can get a good TA to find out for you, but you need to be more specific than just the line.