The lab's boards are carriers for the C865 module: Thundercomm's (the EB5 on the bench [E1]) or our own headset carrier.

How the pieces nest: SoC inside SOM inside carrier

How the pieces nest: SoC inside SOM inside carrier

The lab's C865 SOM held beside the EB5 carrier, labelled

The lab's C865 SOM held beside the EB5 carrier, labelled

The big board is not the RB5 kit board, which is a credit-card-sized 96Boards card [T2].

Name What it is
QRB5165 The chip: Snapdragon 865 silicon sold for robots [Q1]
C865, "TurboX C865", "RB5 SOM" Thundercomm's module: the chip plus memory, storage, power and radio on one plug-in board [T1]
RB5, "Robotics RB5" Qualcomm's robotics dev kit: the module on a small IO board, plus its Linux software [T2]

"We are designing hardware for the RB5" means we are designing a carrier for the C865 module.

Sources