If ya look at the bottom (last post) of any thread you have a choice...
The "quick reply" does NOT give you an "upload image" selection. If you click n "post reply" (lower left) of the last post this will give you this option. It will pop up a new box similar to the quick reply but with the upload image option. (lower left of that box) Just go ahead and try it here after my post. Just click on the "upload images" button, Click "browse" find your pic, double click it in, click okay,,, and your done.

BTW
It won't show up that you put a pic in until you finally click the "OK" button at the bottom when your totally done replying.