What this connector does in the assembly
The Molex 2128720002 is a 68-position SAS/PCIe receptacle from the Series 212872 line. It's a surface-mount, right-angle connector designed to carry high-speed serial data between a backplane or midplane and a storage controller or PCIe add-in card. The 68 positions match the standard SAS-3 / PCIe 3.0 connector footprint — you'll find this on enterprise server backplanes, storage arrays, and RAID controllers where the signal path needs controlled impedance and the board layout calls for a right-angle exit. The integrated EMI shield and board guide are built into the shell, so you don't need a separate metal cage or alignment pins; the shield bleeds common-mode noise before it reaches the signal pins, and the guide takes the shear load during blind mating into a backplane.
Board layout and mounting
That orientation is standard for mezzanine-style card-to-backplane interconnects where the daughter card plugs in at a right angle to the main board. The SMT tails reflow with the rest of the passive components — no separate wave-solder step — but the pad footprint needs to match the 68-position SAS/PCIe land pattern exactly; the datasheet drawing shows the keep-out zone for the shield's ground tabs.