The twitter engineering team’s example of a player card container doesn’t meet [the requirements](http://Twitter Card Forums) describe on the player card card. It specifically says:
“… note that the video has NOT yet begun play, takes up the entire space,…”
The screenshot next to the test case shows a desktop and mobile browser with the video player full width.
However, in the engineering sample of the container:
it has acode that limits the width to a max of 600px:
video {
width:100%;
max-width:600px;
height:auto;
}
This results in video player never being full width on desktop nor any high res modern mobile device.