They have a full pixel display. They are different. E-Ink displays are 1.18mm thick per their spec sheet and you have to add some mechanically stiff backing to that.
Looking at a detailed photo [1] it looks like a STN segmented LCD but I could be wrong.
Incidentally, do you have a pair of callipers handy? Could you measure the PayPal Security Key?
I don't think it is the same thickness as a credit card.
I looked at more teardown pics. It is definitely a segmented display which is far easier to drive than an active matrix (i.e. "pixels"). They also don't have wireless and a host of other things that this device proclaims to have.
They have a full pixel display. They are different. E-Ink displays are 1.18mm thick per their spec sheet and you have to add some mechanically stiff backing to that.
Looking at a detailed photo [1] it looks like a STN segmented LCD but I could be wrong.
Incidentally, do you have a pair of callipers handy? Could you measure the PayPal Security Key?
I don't think it is the same thickness as a credit card.
[1] http://www.stahlke.org/dan/displaycard/front.jpg