The ChartJS widget requires to be placed in a context object (for example, a dataview). The NewChartWrapper in this case is just a dummy object to make sure that you can use the widget.
In normal situations this context object could be something that you use to constrain the data in your graph. In that case the datasource microflow that you create in step 3.6 would have that context object as an input parameter and you would use it to retrieve different data.
Understood. Thank you!