Hi Click on your pic in flickr and then right click on the picture->properties
Copy the link
it will prob look like this http ://farm2.static.flickr.com/1331/1388691971_89cd73332c.jpg?v=0
When u post,click on the image icon(the 1 with a mountain) and paste the link BUT remove the ?v=0 at the end.
Hope this helps