At the bottom left, you will find a representation of the buffer flow. For an interesting view, try this panel in trigger mode. At the top right, you will find a representation of the actual window mode.

Grains are represented by the different rectangles. Find the descriptions of each parameter in the crusher panel help.

The box in the top left corner shows the actual form of the grain window. The small red number gives the actual number of the generated grains at this time.