I use a screengrabber that automatically uploads to my own server so I can quickly share screenshots with people. The images are shared via direct link to the JPG file on my server. I prefer sharing this way rather than flooding my Twitter photo history with random miscellaneous screen clippings, but I’d like the convenience of the image appearing on the tweet.
The Twitter Cards documentation indicates that it requires an HTML page with a fixed image associated with it. Is there any way to support Twitter Photo Cards with direct (offsite) image linking?