That is correct. You upload your photos to a Server, which provides access to it by means of its “address”, which is called a Uniform Resource Locator, aka “URL”.
The middleware (the “BLF BBS Software”) pulls the picture at that URL and displays it. If you enter a URL which does not reference a picture, the BBS Software ignores it. Please be sure to enter something for the size! “100%” will stretch small photos & shrink large ones to perfectly fit the displays of anyone who views it.
Full details here:
HowTo: Adding pictures to posts
and further reading can be found here:
Search For Post Photo
Thank you for making it happen!