Rabbit Ears, Supersized

In my review of the exhibition catalog for the CCA exhibition Imperfect Health last week, I mentioned the SANAA-designed "Rabbit Ear" chair. One version is designed for the Japanese market and one for the United States, the latter following the former by two years. The chair's inclusion in the exhibition and book obviously portrayed one difference between the two countries, yet so simply through a couple similar pieces of furniture. Can you guess which is which?

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[SANAA's "Rabbit Ear" chairs | image sources: left and right]

A little clue:

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[Image sources: left and right]

The chairs designed by Kazuyo Sejima+Ryue Nishizawa/SANAA are actually called Armless Chair and Armless Chair (Wide), part of Maruni's Nextmaruni concept line. The idea behind them (literally) is that the portion of the chair back aligned with the spine is removed, making the chair more comfortable by reducing pressure on the spine. While I'm somewhere between the two gents pictured, I'd probably need the (Wide) version.