Step 1. Find the picture you want to post in your flickr account.
Step 2. Press the "all sizes" button above the picture (See red arrow)

Step 3. Copy the text from the part that says "Grab the photo's URL"

Step 4. Reply to or start a new post on the Boxertrix Forum
Step 5. Type what you want to say
Step 6. Press the Img button once you should see

Step 7. Paste the URL that you got from flickr in right next to the
Thats it your picture should be displayed!![/img]