Currently, on mobile, if you embed a video in an article, there will only be a link (called "Play media") and it directly links to the .ogv video, instead of using our ogv.js player.
Example: https://en.m.wikipedia.org/wiki/User:Fireattack/sandbox/ogv_video
This causes problem on Chrome Android browser (which should be the dominant browser on this platform) since they don't have a native Theora decoder, nor do they plan to ship one. The users end up not be able to see the video.
The video plays fine when it's in-line of the "File:" page, because of the JS player I assume.