Shorthand's Reveal section is a powerful way to show comparisons between two or more images, such as before-and-after shots, or to add or remove layers as the reader scrolls
See, for example:
The overlaying of maps in Two World Collide, by Global Witness
The "then and now" photos in After the floods, by the Telegraph
The lighting strike example, and "peel-off" infographic in Arms Wide Open by BBC News.
Before and after renovation project in This is what it takes to renovate a 99-year-old mansion in New York City by Business Insider
To create a Reveal effect, insert the Reveal section, upload your images, and choose the transition between them. The transitions work on mobile just as they do on web (but remember you may want to upload a different image for portrait screens).
Text overlays and other effects can be added to Reveal sections, too.