What's the need for conductive bridges between the regions of a smart card contact pad?
The ISO/IEC 7816 (see part 2) standard does not define the shapes of the pads, only the minimum size:


  This part of ISO 7816 does not define the maximum dimensions or shape
  of the contacts except for the requirement that each contact shall be
  electrically isolated from the other contacts.


Therefore, it is safe to assume that what you see is done just to make it look nice. You can see the same thing with the USB contacts below: