There's at least ways i know how to upload pictures on a thread. one way is to click on "add attachment" and something should popup giving you the ability to add files you want to add. after that you click on the "insert button" to have be added on the thread.
another way to do it is to click on "insert image" and copy and paste the link of the image you want to upload with the optional choice of adding text although its not necessary.
out of the two. the first one is easier to manage.
