There has been no behavioral change to how Player Cards appear in a timeline. The “view media” link on web and the play button indicator on mobile have always been the way to identify and view the contents of a Player Card. This is even true for YouTube on web and mobile as seen below. There are no super-white-listed services other than Twitter owned and operated products (e.g. native photo upload, native video upload, Vines, Periscopes, promoted content, etc).
That being said, we have run experiments with subsets of users to see how media forward content, other than our own, is received when displayed in the timeline. We certainly see the value of media forward for developers.
Concerning the Cards Validator, it allows developers to see what their content will look like after a Tweet has been expanded. I will admit this is not clear and can easily be construed as how a Card will appear within a timeline. I will pass this feedback along to the Cards engineering team to address the ambiguity. Perhaps a duel preview; “here it is in a timeline” and “here it is when expanded.” If you have further feedback along these lines, please let us know.
@deanswaydesign, you are correct that at the moment attaching a video via the web is not available. While prioritizing the features related to video upload, mobile upload took top precedence as the majority of our users are on mobile and take videos on their mobile devices. That was followed by adding video upload capabilities to the media/upload endpoint for developers to include videos within their applications. Upload on web would be a logical next step.
The SSLv3 and RC4 requirements mentioned are beyond my technical knowledge of the Validator backend, so I will create a ticket for the engineering team for this feedback.
If anyone has further questions, please let me know.
As referenced above, YouTube Tweets on the web:
YouTube Tweets on mobile: