"I don't see any difference between saying "nice boob job" to LW4 and saying "nice rack" to any woman. It's rude. "

Not the same thing. It's more like "Nice facelift" or "Great botox job". Maybe that's rude too, but at least it's analogous. It's very different to comment on a change -- clearly an intentional change -- than on something that just is the way it has been.