So…I figured out that we were using the twitter:player:stream and twitter:player:Stream:content_type meta tags even thought we weren’t using a raw .mp4, which is probably why the image link to the player was broken. After I deleted those tags, the link opened the simulated browser to the URL indicated in the twitter:player meta tag.
However, it’s still disappointing that a preview image does not show on mobile to indicate that the tweet is a player card and can be interacted with. YouTube and SoundCloud links on mobile will usually show an image for their player cards by default. How can I do the same thing?