In the google screenshot , its a combination chart ( pareto/bar + line) . It has got two y axis.
Bars represent frequency of that particular category. Represented by left yaxis.
The line represent cumulative % . Represented by right yaxis.
X axis is various categories (reason for coming late )
In your screenshot, % of cases for traffic seems to be approximately 32% .
% of cases for child care seems to be approximately 28% . So cumulative % at childcare would be 32+28 , which is approximately 60% . This is 60% is plotted on the line (look at the right y axis).
The scope of the lecture seems to be just bar pareto charts, for which categories in x axis can be plotted either ascending or descending.
For combination pareto chart (bar + line) , it makes sense to keep the categories descending since you are trying to plot the cumulative line from 0% to 100%.