In 2007, the residency card for EU citizens was replaced by an unwieldy piece of green A4 paper, known as the "certificado de registro de residente comunitario". This year, the A4 paper has been replaced by a smaller card (credit card size), still green and still without a photo, but much easier to fit into a wallet or purse.
If you would like to change to this new format, the Comisería in Elda say you will have to go through the full process again, filling in an EX-18 form (available from the Internet) (or an out-of-date EX-16 form from the Comisería!), handing in your old green form together with a copy of your passport, padrón (less than 3 months old) and NIE, and paying €10,20.
Incidentally, if you are already on the register and change your address or your passport you are expected to update the details at the Comisería each time a change occurs.