This is hardly new. I remember collecting ebooks on 4chan circa 2005 via this method. The fact that it was a jpg allowed you to post it on the imageboard with the zip/RAR file therein containing a txt/doc/rtf of the ebook.
And yet, nobody has done the same for Twitter until now.
The difference is that twitter applies a series of operations to all uploaded image, stripping EXIF data, recompressing, etc., which would normally be difficult to work around.
Did people do this back in the day? 4chan used to be totally fine with just uploading a jpeg concatenated with a zip, but I haven't seen this ICC profile trick before today.