I'm using the Twitter REST API to automate posting statuses. Sometimes, it may be possible that multiple statuses can have the same image attached.
Do Twitter allow to use the same media_id for multiple statuses? This could avoid to upload multiple times the same image on the Twitter servers.
Unfortunately, you cannot re-use the same media_id in more than one tweet. If you try, you will get this error: {"code":187,"message":"Status is a duplicate."}. Even if you post tweets with different text, you will get the error.