The control panel in Nexus puzzle

//ads -- adsterra.com -- native banner
?>
In The Dig, where do you get the clue to solve the puzzle in the control panel in Nexus? I'm talking about the alignment of the lens for the power source, as show here:
When I played the game I had to grab a walkthrough just for that part. But nowadays this still bugs me.
Pictures about "The control panel in Nexus puzzle"



Resident Evil 2 Leon 2nd Run Electric Door Puzzle
Sources: Stack Exchange - This article follows the attribution requirements of Stack Exchange and is licensed under CC BY-SA 3.0.
Images: Mike B, Mike B, Dmitry Demidov, Andrea Piacquadio