So basically, it's a meme originating from Star Trek wherein a species communicates exclusively through idioms and descriptions of events, making it impossible to translate without an understanding of their overall culture and history. Shaka When the Walls Fell probably means failure, it can be translated as "wow" in best case or "this is devastating" in the worst case.
If my Ink Tank Printer suddenly posted SHAKA WHEN THE WALLS FELL then I would be taking a few steps back and grabbing some towels.
This almost sounds like a prediction of contemporary meme culture where every situation or emotion is conveyed though a shared collection of phrases and images.
I always thought this was a funny scene, because if you know what the parts of a printer are called, it’s obvious what “PC Load Letter” means. So Michael is obviously just bad at his job.
Load letter sized paper into the paper cassette, in case you didn’t know.