You have a segmented e-ink display in there.
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 do have a PayPal Security Key. My calliper measures 0.81mm, compared to 0.78mm for credit cards. So it is indeed pretty much the same thickness.
Thanks.
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.
No, I have in my pocket a PayPal Security Key: it is the same size and thickness and flexibility as a credit card, yet it houses an e-paper display: https://www.paypal-community.com/t5/image/serverpage/image-i... They have been on the market for 5+ years, so the technology is there. Plastc has a bigger display, but there is no doubt it can fit in a credit card because an e-paper display does not require that much supporting circuitry. See this guy who tore down the PayPal card: http://www.stahlke.org/dan/displaycard/