Multimedia
Basic Embedded Images:
Camera phone generated images.
Basic embedded audio
Quicktime container is entrusted with MPEG-4 AAC audio stream and an OGG container format handling a Vorbis audio stream. Your browser is using the first one it can deal with.
Basic embedded video
Camera phone generated the original mp4 container format, H.264 video stream codec, MPEG-4 AAC audio stream codec.
FFmpeg used to convert that original file into ones with WebM container and vp9 video stream, and OGG with theora, of similar video bitrate.
Your browser has chosen whichever one of these it found acceptable.