Well, that's just it. They don't say. You kind of take it on blind faith. It's a room that THEY deem an upgrade from what you have - and then you have to take it. However, some say that what they consider an upgrade may not be exactly what you want and then you're obliged to take it. It may be the same room, only in a better location, or a better room, but maybe not in a location you want. OR one of the best cabins on the ship!!! Anyway, it's a last minute thing from what I understand, if you want to gamble.
j.