This prop started out as the "long range scanner" that sat atop the Jupiter II. The scanner was normally housed beneath a circular door. When needed, the door would open and the scanner would rise up out of the roof of the Jupiter II.
This particular prop would be reused frequently throughout the run of Lost in Space, but here are a few images of the "scanner" in its most prominent incarnations.
["The Derelict." Episode Production Number 8502. First broadcast 22 September 1965]
In this incarnation, the scanner forms the "torso" of the female-voiced robot from "The Ghost Planet." Inside the cage of the scanner, you can see one of those cut-glass dome controls from the map room of the Derelict space ship. It illuminates along with her head when she speaks.
["The Ghost Planet." Episode Production Number 9503. First broadcast 28 September 1966]
The scanner is again used for the evil female robot in "Deadliest of the Species." Indeed, the basic design for this robot is the same as the robot above, although her neck has been elongated and the body of the scanner's cage has been filled in. Arms now project from two of the oblong radar dishes on the side of the scanner. It is interesting to note that all alien robots that appear on Lost in Space have the same basic arm and claw design as the B9 robot.
["Deadliest of the Species." Episode Production Number 1504. First broadcast 22 November 1967]
I asked Robert Kinoshita whether he designed any of these female robots. He replied that not only did he not design them, he thought they were horrible. He suspected that they might have been designed by Paul Zastupnevich.