Thumbnail image for videos a must?

Is it correct that I have to add a thumbnail image to (online) videos? What I don’t like about it is that the user now has to tap the video twice to get it playing. I tried adding ?autoplay=1 to the link but it doesn’t help.

@Friedo you are correct, a thumbnail is needed for each video.

My understanding is that if it is not done this way then any video that comes upon the screen would start downloading even if not played.

I don’t seem to be able to build an app without specifying a thumbnail image:

So it’s a requirement, I think. It would be helpful if the video started playing as soon as the thumbnail is tapped. At the moment, a second tap is necessary to actually start the video.