Every day, one mosaic. Fit the stones so the day's Laws hold, and the abstract colours settle into a picture of something real — a nautilus shell, the Crab Nebula, terraced fields on a hillside. A few lines tell you what you have just assembled.
There is no clock. Nothing is lost by stopping and coming back. The same mosaic goes to everyone in the world on the same day, so it is worth talking about with whoever else is solving it.
Terrazzo is built to be a calm place. No timers, no advertising, no pressure, and no account to make.