Assuming this is the photo you're wanting to post since it's the only one in your image gallery:

[Linked Image]

At your image gallery left click directly on the picture you want to post. It should open up to a medium size image. Right click and copy that image info to post a medium size image, or, to post your photo in full size left click again then right click and copy that enlarged image info. Now simply paste the image info in the Campfire's 'Insert Image Link' at the top same as always.