Upload the image to any website, like imageshack or something, and then copy that link. Click on the "Insert Image" button, paste the link to your photo, and the picture will be shown in the post
I do know this - xenforo dropped the ball by not keeping the vbulletin reputation comments as a feature. The loss of the Reputation comments data when we switched to Xenforo really was the death knell for the site when it came to all the users that left. I know I missed it so much and I got way less interested in the site when that feature was gone and I run the site.