I have two observations and/or questions.
1.) In this shot from "Where No Man Has Gone Before" (http://tos.trekcore.com/hd/albums/1x...eforehd271.jpg
), the play of light and shadows make me think there was a lamp or lamps behind the wall against which the bed was set.
2.) On the biobed monitor, there is the "Recorder" indicator which always appeared in the on position. How did someone turn off this recorder?
Yes, there are lights behind that wall, up by the over-bed monitor. Donny appears to be using he purplish light from the second season (like "Journey to Babel") instead of the plain white light from he first season (like "Where No Man...").
I think the "activate recorder function" is probably contolled from the same switch over on the side of the monitor: the switch that Dr. Mark Piper uses while checking out Gary Mitchell, is amazed that Gary's readings aren't off slightly to some degree or another, and performs a test on the monitor. (You can see the "Test" talkback being illuminated, and the little triangular measurement indicators all move to absolute mid-line center during the test. The "Test" light goes off and the indicators all go back to normal fluctuate-y positions when he turns the test function off. Presumably the Record function is over at that same switch--maybe a three way toggle.)