On Fri, May 3, 2019, 06:21 Liam Proven via cctalk <cctalk at 
classiccmp.org  
wrote:
 It looks to me like an Apple "live photo".
 
Google/Android's version of the same. In a couple cases (like the CM's LED
panels) I used it intentionally to capture motion. In others, I had
forgotten to shut it off :(
I can/should go back and save stills out of the motion clips for those
where I didn't intend to use it.
j