This indicator is very simple: it shows signals triggered using two different ZigZag indicators (fast and slow) without any filtering.
It does never -ever- repaint a past signal and therefore is useful to study the real behavior of the ZigZag indicator -which does repaint- as a trading tool over time.
As you can see, many signals are repainted by ZigZag indicator over time. Fractals have been used to reduce the number of highs and lows painted.
It depends on original MetaQuotes ZigZag indicator -attached-.