Keep in mind you are probably using server space by uploading multiple images at once, that others pay for. Is there a reason why you want to upload many images at once?
Microblogging is the name for things like Twitter. You "blog" only small texts like the famous 160 characters of Twitter. A tweet or toot would be called micropost or just "status update". On microblogs you usually don't have threads but replies to a post. These replies and the initial post effectively form a thread but all the replies are also separate posts by the user.