Reader Chris DePrisco had the incredibly irresponsible yet somewhat awesome idea of programming this automated laser to sing the GLaDOS summoning song, using what I am assuming is different levels of intensity to match the tones of the song. The markers are labeled with the lyrics of the tune, with the whole song resulting in the Aperture Science logo etched on a stainless steel plate.
It took quite a while to get it this far. Laser markers weren't really meant for making music and there are a few parts out of time but I'm sure GLaDOS would approve.
I've a feeling she would approve. She'd say so, just before reprogramming the laser to burn a stunning rendition of Portal 2's "Want You Gone" on Chris' torso in the shape of a massive torso-sized hole.
She's so lovable.