[untog]

It likely can't - videos are enforced as tap-to-play on iPhones, no matter what.

Which is good in most ways, but also means that people are converting videos into hugely bandwidth-wasting GIFs instead. I'd rather videos be "tap for sound" and autoplay at this point.

[drannex]

Setting a javascript script to simulate a click should be enough to autoplay the video on mobile (on body load, click once on video).

[untog]

It would still take over full screen display, which is clearly not the intent.