A Series of Statistical Charts Illustrating the Condition of the Descendants of Former African Slaves - Diagram shows value of property owned by African Americans in Virginia, North Carolina, and Georgia [LCCN2014645361]
The pattern
This still is filed under Data as proof.
Define
A chart, map, or count that is the argument, not an illustration next to the argument.
Mechanism
Sighted evidence. The reader is asked to believe their eyes: a bar, a share, a spread on a map.
Verdict
The claim is comparative or quantitative and the figure can be read without a caption doing the sell.
Why it works
This is a total dressed as an object, not a chart. The four equal triangles are deliberately not proportional to their figures, which sacrifices comparison between the three states in exchange for one indivisible square that reads as a single mass of wealth. Reversing white lettering out of flat saturated colour makes the numbers part of the artwork rather than captions on it, so the figures get looked at instead of skimmed. Putting the total in the black triangle at the base makes it the ground the other three sit on. Converting to francs on the face of the plate removes the one step of arithmetic that would have let the audience disengage.
Steal this when
When the number itself is the argument and a proportional chart would only invite quibbling about the components. Build one geometric container, put the components inside it, and put the total in the visually heaviest position.