It seems that Visa is not too keen on the "chip 'n' signature" security that iZettle uses, even though the Swedish company says it has a lower fraud rate than for chip and pin transactions.
Between the plastic and the display is a flush black bezel that gets a bit thicker on the top and the bottom, housing the trademark "n" home button -- a signature, the company explains, that helps people orient the device even when the screen is off.