They've changed it recently.
Go to the pic you want, then click on "Share this" at the top of the pic.
Select "Grab the HTML" from the drop down
Select BBCode
Copy the html code, then just paste it into your post...
You'll have the pic, and a link (get rid on the last {url} {/url} bit if you don't want the link
self_portrait by genki_na, on Flickr
Hope that works for you -> don't make me do screenshots!