It sadly does not. IIRC: lemmy.world devs removed this function a few updates ago because it was using up a lot of server CPU. I’d like for them to resolve it in the next update.

It relates to the video that OP shared here. It’s the thumbnail of the video.

I’d like to see more videos posted with their thumbnails on Lemmy. So I periodically comment on videos that don’t have them yet.

Here is the video’s thumbnail.

I use an Extension called vidIQ to find and use the video thumbnail easily. The current thumbnail will be shown just below the video view count.