The Robot's statement, "There are more jamming potentials on this planet, Will Robinson, than can be computed by my computer banks," is a variation of, "There are more things in heaven and earth, Horatio, / Than are dreamt of in your philosophy," from Hamlet, Act 1, scene 5.
When Dr. Smith is eating the imaginary dinner, the robot comments that "you may be eating it more, but enjoying it less." This is a reference to a Camel cigarette ad of the era, which asked viewers if they were "smoking more now but enjoying it less."
The eye and eye stalk of the machine which creates illusions appears to be based on the Martian spacecraft in The War of the Worlds (1953).
A Fifth Columnist is a member of a clandestine subversive organization who tries to help a potential invader.
The green "planet" is the same one used when the Spindrift went into space warp on Land of the Giants (1968).