If I were Desmond, and doing laundry for two at most, I would have selected a top-end AEG with ventless condensation dryer. But that's just me.
None of the Duet-type machines (Kenmore, kitchenaid, BIG, etc) comes with a ventless dryer option, which would make the most sense in a place where you might want to control ventilation or recycle water.
I think TPTB just picked the Hetties (a slang term for HE3/4t's) because they look all futuristic and cool, and are new enough to be a clue. Any european front loader with a ventless dryer would not be an obvious "anachronism" since they have been around long, long time.
I don't think they considered hiding the dryer exhaust.