如何让移动设备显示图像而不是视频？

I'm trying to get mobile devices to display an image instead of a video. The code I have works on all browsers that I have tested. On mobile it shows the video with a play sign instead of auto-playing (I believe mobiles do not auto-play). I would like a still image to show instead of the video, is this possible? I'm trying to get mobile devices to display an