If you’ve taken classes that cover image processing, you’ve likely come across the Lenna image. It’s a headshot of Lena Forsén taken from Playboy Magazine in 1972. For The Pudding, Jennifer Ding, with Jan Diehm and Michelle McGhee, looked at use of the image in research over the years — despite copyright claims and Forsén’s wish for researchers to move on to a different image.
Ding used a straightforward bar chart to show the pattern over time, but the annotation provides a layer of context that tells you what those peaks and valleys mean.