As a clarification, the bottom-most balcony (Dolphin deck, I believe--the minisuites) are fully visible from all above. They are not under cover, but fully exposed to the sky above. The balconies on the next deck above that are tiered back from the exposed balconies below. They are twice as deep as a standard baclony (These balconies are 9' wide by 10' deep. All balconies above this level are standard--about 9' wide by 5' deep). The inside half of each balcony on this deck is under cover and the outside half closest to the railing is open to above. The balconies on the remaining decks above are not tiered. They are all in line with the middle of the balcony below--hence the reason for the extra deep balconies being half under cover and half exposed to above.
Sorry, this doesn't answer your question though.
We were on the Grand last year, and I actually think I do remember walking past balconies in the area you speak of on Emarald deck. This is right where the stairs take you from the Promenade deck up one level to the Emerald deck where the promenade continues around the front of the ship. If I remember correctly, these balconies aren't completely private. I don't think anyone walks directly in front of them, it's just that the stairs and upper promenade adjacent these rooms allow a bit of a glimpse into these balconies.