Reuse? I never heard of reusing a jpg which is an image. I even googled it. Do you mean copy and paste an image?
Not exactly. I was expecting to upload once and they retrieve in different threads and have each instance work the way it does when you put one in one thread.
If I copy from one thread to another clicking on it does not enlarge it like it does in the original thread. And . . . there seems to be no way to retrieve a .jpg that has been uploaded and then reuse it in another thread.
Try getting the URL of the picture, e.g. right click on picture select open in new tab. Then copy that URL and when you post a comment click the picture icon in the post toolbar and paste the image you should then see [ I M G ] your pasted url [ / I M G ] (minus the spacing)