LOL, I see what you meant now.
When you upload and attach an image here using the usual method below, then you will be able to click on it to see it in full size by default. This is the prefered method here so that you don't have to worry about broken image links in your posts in the future.
Screenshots and Files - Upload and Post in Seven Forums
Otherwise, you could click on the "Insert Image" icon on the toolbar to add the URL link to the image. When it's posted, it will have the "Click....." link bar on the image like you wanted.
To do this manually using BB codes
, you would type this:
[IMG]URL link of image[/IMG]