I’m currently working a Player Twitter card implementation, but it seems that the validator isn’t working (it’s just showing the image:src - without being able to play it. Even when I’m testing with YouTube links it’s not working (which makes me think the validator is broken - combined with the many other posts I saw about this subject).
However, without the validator it’s difficult to test whether the iFrame is set up OK. Is there any way to test? Are there any guidelines for the content of the iFrame (technically speaking)?
I’d like the Twitter card to be perfect before applying for the Twitter card.