Many times by adding an extra dimension to a chart, the designer unwittingly confuses his audience. The rectangle plot is useful in very specialized situation but as used here, I still haven't figured out this chart.
Part of the problem is my own ignorance of this subject matter. I cannot understand how 0-100 constitutes "poverty level" and if it represents percentiles, then the reader needs to know of what?
The biggest problem is that the widths of the rectangles are not labeled. The labels on the y-axis are categories and most definitely not widths.
These rectangles draw our attention to the areas and yet it isn't clear what is being measured. It appears to be the number of dead people in thousands who belong to some poverty-defined demographic. In any case, the human eye is also not trained to compare the area of a fat, short rectangle with that of a tall, slim rectangle.
Reference: "The People's Epidemiologists", Harvard Magazine, March-April 2006.