I've spotted some very weird functionality on Facebook that I've been unable to replicate. The following FB page: https://www.facebook.com/streetfx/ has a video pinned to it's wall with the text overlay "HER FIRST TIME IN A GTR". If you view this from the iPhone Facebook app, when you click on the video (to fullscreen it with sound), it opens up an external article. Some pages are even adding a fake watermark "click for sound" to trick you into clicking the video, which then opens an article. How is this possible?