The indicator plots arrows on the bar, if its close price is greater than close price of the previous bar.

The color, width, shift and code of the arrow char changed randomly after N ticks. The N variable is defined as input parameter, it can be changed using the "Properties" window. Note that initial properties of the plot1 graphic plot (DRAW_ARROW) are defined using the #property preprocessor directive, further these properties changed randomly (OnCalculate() function).

See also: The Drawing Styles in MQL5.