Vid 20170309 Wa0010 Mp4 -

The date the video was created or saved to the sender's device (Year/Month/Day).

A sequential serial number used to distinguish multiple videos sent or saved on that same day. Why You Might Be Seeing This VID 20170309 WA0010 mp4

Trends like the "Mannequin Challenge" were still being shared in various forms. The date the video was created or saved