On iOS/Android, if the page has a twitter:player:stream, it will be loaded, if there’s none, taping on the poster frame will open twitter:player (the same URL used by the IFRAME on Desktop twitter.com).
To test twitter:player on iOS/Android, the simplest is just to open that URL in Chrome on your device. On iOS, you should also try opening it in the Twitter app itself (just tweet the twitter:player URL and then open it).