Adding additional information in "hidden" boxes

My boss shared this Washington Post story with me: https://www.washingtonpost.com/world/national-security/islamic-states-embrace-of-social-media-puts-tech-companies-in-a-bind/2015/07/15/0e5624c4-169c-11e5-89f3-61410da94eb1_story.html?kmap=1&pr=1

Instead of having all of the infoboxes in the sidebar, which is cluttered, users can click on a highlighted portion to bring up additional information. Wondering if this would be something for future development?