It would not have been a mistake in terms of every floor above and below this unit has it in the as-drawn position, but this one doesn't. Somewhere along the way, plans changed for some reason, and the only way to find that out would be to go through the right people at Lanterra (that could take some time, or might never be answered) as to why.
Anyway, if the door that slides in that pair of glass panels pictured above is the one that's closer to the wall, then the arrangement as show in the suggested furniture layout should still allow you to walk out to the balcony between the couch and the corner chair.
42