When Sheila presses the button, from the device hanging from the ceiling of the chamber a line of light extends, passing through the screen nearest to it. Since it's a mesh the light can pass across, until it reaches the second cubic chamber at the other side of the walkway, right into its wall.

Looks like this hanging device and the light form some sort of zipline, with its route passing through where all the prickly screens are at. Only one zipline device and it doesn't seem like more can appear, though. Only one person can use it.