Motion Photo or Samsung Motion Photo is a feature of Samsung Phones introduced around 2016, and has been added to some Google pixel phones as well and works similar to Apple Live Photo. In the case of Samsung phones by default the camera app captures video before the shutter button is pressed and appends it to the end of the picture file. The posts here most likely to have this extra video embeded are sketches or traditional art that was photographed with said phones rather than flatbed scanner. The easiest way for detecting if the picture is a Motion Photo is saving and opening the picture up in the updated Windows 10/11 photo app (version 2023.11090.20015.0 or greater on PC ). Doing so on such a file will open the picture normally with the addition of a MOTION button on screen, clicking which will play the video file. https://blogs.windows.com/windows-insider/2023/09/14/windows-photos-gets-background-blur-search-motion-photo-support-and-other-enhancements/