8170 balcony is about 3 feet wide then 2 feet wide at corner. It does not wrap around. Since ship is flat at stern folks above should not be able to see into balcony below. No windows--just sliding door.
PS---cruisestateroom.com has the wrong pictures for penthouse suites. I spent an hour on the phone with NCL looking at these photos and they said the penthouse suite photo is for suite AB as it shows 2 separate rooms.
Photos at cruisesonly.com are correct.