A Series of Statistical Charts Illustrating the Condition of the Descendants of Former African Slaves - Diagram shows number of African American almshouse residents [LCCN2014645375]
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
The chart is a controlled comparison disguised as a bar chart: national black and Philadelphia yellow are colour-separated and physically gapped, so the reader reads two datasets, then the curly braces name them and force the pairing. Within the yellow group the bars are ordered slum, mixed, better - descending - which turns class into a visible gradient and lets the chart argue causation without a sentence of text. Putting the highest and the lowest bars in the same colour is the whole rhetorical trick: it proves the range sits inside one population and kills the racial reading. Labelling each bar with its exact rate above the tip removes any need for an axis, gridlines or tick marks.
Steal this when
Steal this when an average is being used to indict a group and the real variance lives inside that group. Splitting one population into ordered sub-segments in a single colour is the right structure whenever you need to show that the spread within a category is larger than the gap between categories.