Moving right along, yeah you can see the extending "hero" prop a few times in the show... early on when the guys are lasering the top of the rock knoll just after Captain Pike is abducted...
Also in this scene you see Navigator Jose Tyler stop,
rotate the barrel to bring another of the emitters in line (there are three emitters), and resume blasting away
Later, in the underground cell, Pike tries to fire a laser brought down by a rescue party... he extends the emitter, tries again, and concludes that the aliens are creating an illusion that the weapon is "empty"
The middle ring on the emitter barrel also rotates and slides... near the end of the story Number One (Majel Barrett) fiddles with this ring to put the laser on "overload"
What isn't clear to me, is if the ring is "loose" and just slides around free, or if there is some sort of mechanism to "capture" it, so it only turns and slides a certain way.
The prop later turns up in a couple of other Star Trek episodes, with very obvious
screws under the barrel, which makes me think the ring was "loose"
Here's another shot of the prop as it looked after the modifications it got in the second pilot episode.