To make this reply, first, I opened another browser tab. I then searched out the image location (FSM requires the image be hosted somewhere on the net, flickr, photobucket, etc,) I right-clicked o nthe image, and used "Save Image Location."
Then, I chose the "Use Rich Formatting" in the Reply window.
From within the rich formatting window, I selected "Insert Image" button (just to the right of center in the bottom row at the top of the edit window). Which opens a box which asks for the image location. I used CTRL+V to paste the saved image location data. I could have used right-click and selected "Paste" as easily.
the image, and white control dots appear around it. IHovering the mouse over the BR one gave an arrow, which I used to drag the image to appear like this:
Any online source for images can generally work this way:
(AutoCAD rendering of street sign models)
The only thing to watch for is that the file structures or permission can change
Hope that helps some.