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Now, it redesigned the Gmail contact cards, which show up when you move the mouse over a contact in Gmail. They still contain an image of the contact, their e-mail, and links for quick e-mailing, chat and video chat (together with several other options), but those buttons have moved from the top to the bottom of the card, and the card has lost the light blue border, making it look more like a business card.
Interestingly enough, you can no longer edit the name of the contact directly from the card (you can do it in the address book), but you can still change their pictures.
These are all very small, cosmetic changes, but put them all together, and you'll see that Gmail has actually changed quite a lot in the last couple of years.