It seems that a lot of the videos I see on Facebook, from various sources, have an initial image that I get a glimpse of as I scroll down to it, but then disappears in less than a second. I often want to look at that starting picture for longer, but no matter what I do I can’t get it to reappear. I can “rewind” the video to the beginning but it begins with what came immediately after that first image. I’m curious as to why this happens, and if there’s anything I can do to get a longer look at that image.
I’m wondering if that’s meant to be the thumbnail/preview. I don’t know if it’s still happening, but it used to be common for people to put a clickbait type picture in the preview, but that image had to appear somewhere in the video to use it, so they drop a single frame of it somewhere that’d you wouldn’t notice. For example, you might see a video called ‘all time funniest fails 2017’ and a picture of a girl in a bikini holding a beer bong. The actual video would be your normal fail videos, but you’d never see a video of the beer bong girl. Or at least you’d never see it if someone in the comments didn’t tell you the time stamp of exactly where to look.
In any case, I’m guessing that’s it. What you’re seeing is a single frame hidden in it somewhere. When you scroll down to it, the video auto plays so you only catch a glimpse of it. If you block auto play, you might be able to look at it for longer.
Don’t know if this works in Facebook (which I never use) but in Youtube videos you can press , or . (comma or period) while paused to step frame by frame through a video. Might be worth a try.