The Mosaic generator function renders a symmetric pattern, which consists of randomly arranged lines.

Each individual mosaic pattern is defined by its Random Seed value. The Time Offset attribute has no effect here.

The width of the lines is adjusted with the Object Radius parameter. The Size value defines the half-width relative to the smaller side of the texture's dimensions. For example Size=1% on a 200x400 texture gives you lines, that are 200*2*1%=4 pixels thick.

Tip: Increase the Object Radius and invert the colors to get a flagstone mosaic pattern (Image 2)