The Twitter @username the card should be attributed to.
Max 200 characters.
This must be a HTTPS URL.
Image to be displayed in place of the player on platforms that don’t support iFrames or inline players. Image should be same dimensions as your player. Images with fewer than 68,600 pixels (a 262x262 square image, or a 350x196 16:9 image) will cause the player card not to render. Image must be less then 5MB in size. JPG, PNG, WEBP and GIF formats are supported.