I am stealing what Rich posted because he gave perfect step by step on the way to do it and now you have it on this page and don't have to go back to look at it. And his is prettier than the tutorial I did on Upland Journal

Plus his is more relevant than my eagle shots.
Looks like you got the privacy setting changed to public, so your getting closer!
Before you said that you didn't have the option to copy. And I didn't either but now I do.
Make sure you are not trying to copy the URL path in the top of your browser window.
Go to your picture, and click the icon that is circled in this photo:
You will get a box that comes up in the center of your screen. Make sure you click on the tab that says BB Code first though
And now you can copy the text that is highlighted in the box. And then paste it into your reply where you want the picture.
Once you get used to it you will not even think about how to do it.