When the camera first follows Klaatu into the interior of his spaceship, we witness the first gestural interface seen in the survey. To turn on the lights, Klaatu places his hands in the air before a double column of small lights imbedded in the wall to the right of the door. He holds his hand up for a moment, and then smoothly brings it down before these lights. In response the lights on the wall extinguish and an overhead light illuminates. He repeats this gesture on a similar double column of lights to the left of the door.
The nice thing to note about this gesture is that it is simple and easy to execute. The mapping also has a nice physical referent: When the hand goes down like the sun, the lights dim. When the hand goes up like the sun, the lights illuminate.
He then approaches an instrument panel with an array of translucent controls; like a small keyboard with extended, plastic keys. As before, he holds his hand a moment at the top of the controls before swiping his hand in the air toward the bottom of the controls. In response, the panels illuminate. He repeats this on a similar panel nearby.
Having activated all of these elements, he begins to speak in his alien tongue to a circular, strangely lit panel on the wall. (The film gives no indication as to the purpose of his speech, so no conclusions about its interface can be drawn.)
Gort also operates the translucent panels with a wave of his hand. To her credit, perhaps, Helen does not try to control the panels, but we can presume that, like the spaceship, some security mechanism prevents unauthorized control.
Who knows how Klaatu perceives this panel. He’s an alien, after all. But for us mere humans, the interface is confounding. There are no labels to help us understand what controls what. The physical affordances of different parts of the panels imply sliding along the surface, touch, or turning, not gesture. Gestural affordances are tricky at best, but these translucent shapes actually signal something different altogether.
And you have to wonder why he has to go through this rigmarole at all. Why must he turn on each section of the interface, one by one? Can’t they make just one “on” button? And isn’t he just doing one thing: Transmitting? He doesn’t even seem to select a recipient, so it’s tied to HQ. Seriously, can’t he just turn it on?
Why is this UI even here?
Or better yet, can’t the microphone just detect when he’s nearby, illuminate to let him know it’s ready, and subtly confirm when it’s “hearing” him? That would be the agentive solution.
Maybe it needs some lockdown: Power
OK. Fine. If this transmission consumes a significant amount of power, then an even more deliberate activation is warranted, perhaps the turning of a key. And once on, you would expect to see some indication of the rate of power depletion and remaining power reserves, which we don’t see, so this is pretty doubtful.
Maybe it needs some lockdown: Security
This is the one concern that might warrant all the craziness. That the interface has no affordance means that Joe Human Schmo can’t just walk in and turn it on. (In fact the misleading bits help with a plausible diversion.) The “workflow” then is actually a gestural combination that unlocks the interface and starts it recording. Even if Helen accidentally discovered the gestural aspect, there’s little to no way she could figure out those particular gestures and start intergalactic calls for help. And remembering that Klaatu is, essentially, a space ethics reconn cop, this level of security might make sense.