It's a different way of visualising wicks, which can clarify sentiment and be a useful way to understand wicks better in general. One way to use it is to look for clusters of 3/4 larger bars in a row, which generally helps to determine future direction especially when seen at important levels.
In true TradingView spirit, the author of this script has published it open-source, so traders can understand and verify it. Cheers to the author! You may use it for free, but reuse of this code in a publication is governed by House Rules. You can favorite it to use it on a chart.