Null and Void
At the beginning of the episode, we get a shot of Jack standing in the foreground of his office, with his desk sitting behind him. He’s talking to Ianto, I think. Anyway, on Jack’s right (the viewing left) sits a table lamp – and hung over the rim of the lamp’s shade… a pair of 3D glasses, presumably the ones the Doctor used to view the void stuff while at Torchwood One (in Army of Ghosts and Doomsday). Doubt Ianto had the time or inclination to pick them up while rescuing his girlfriend, so seems more likely they were salvaged from Torchwood after the Doctor sealed the rift into the Void.