Ipad 4 vs Ipad 3 Box Differencies

Hello

I went to the store today to buy un i pad and i asked for the new ipad 4 the one with the lightning connector and the A6X proccessor .The seller showed me the ipad and it was in the box but he didn't knew if it was ipad 3 or ipad 4.and he told me that he cant open the box to see it. How can i spot if it is ipad 3 or ipad 4 from the box?

Thank you