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.