Just found some info about the B-17G s/n. 44-85784 - it seems that there were two pods installed.
The Starboard pod was a manned gunner position and the port pod had remote-controlled weapons.
They were testing possible turret systems for the XB-52.
The Starboard pod was also occupied by doctors doing research on the effects of having a person in such a position on an aircraft, similar to their experiments with a cockpit mounted on one of the P-38's booms in order to test assymetric pilot/crew stations (like the P-82, for example).