I had trouble figuring it out, too. It was so different that anything I was used to. See if this helps:
After the photo is uploaded to your library, double click on the pic.
On the right it will have 4 boxes under "SHARE LINKS". Click on the bottom box (IMG). It will say "copied".
Then go into your post and paste it. (I use ctrl V, but any way to paste will do.)
He prayeth best, who loveth best, all creatures great and small.