What is the purpose of the dark cloud in The Witness?

At one point in The Witness, you can aim a reflection of one of the lasers at a dark gray cloud, and it will light up. Is there any point to this? Is it simply an easter egg? Or is this a puzzle of some sort?

In case it helps, I have beaten the game, but not 100%'ed or gone through a second time.

Solution 1:

This is one of the many environmental puzzles in The Witness. What you want to do after illuminating the cloud is run down the stairs from the tower you're on, go straight and follow the path. Eventually you'll cross a small bridge, at which point you'll want to turn right a bit, towards the central mountain. You want to go as far as you need to be so that when you turn around, the clouds form a squiggly line, which you can now complete.

Here is a video solution of where exactly to go: