Gif: "Can someone please tell me how to achieve this effect?"

https://gph.is/1sCZ0Vc I need to make something like this for a project. It would be great if someone could tell me how this was achieved and what this effect is called via /r/Cinemagraphs https://www.reddit.com/r/Cinemagraphs/comments/8j4vo9/can_someone_please_tell_me_how_to_achieve_this/?utm_source=ifttt