Ehm, why should we flag a full sized Twitter post? I thought we don't flag duplicates.

It's not full sized -- https://pbs.twimg.com/media/CyBzhZiUAAAYk3I.jpg:orig is the original, but there's no point in uploading it since the pixiv version is already uploaded. Take a look at the resolution difference.

MD5 mismatch of http://pbs.twimg.com/media/CyBzhZiUAAAYk3I.jpg:orig