What are the URLs of images?

Hi, I've noticed that the URLs of images on vbulletin forums are masked. For example, the image in this post is qemu.png, however, the only URL given for it is

Code:

http://www.wilderssecurity.com/attachment.php?attachmentid=194558&stc=1&d=1193775325

As you can see, that URL doesn't end in qemu.png, so it's not the actual URL. The actual URL probably looks something like this:

https://www.wilderssecurity.com/attachments/qemu.png

I find it to be interesting that a website can actually hide a URL of something from me and at the same time display it directly. I also mainly want to know because it would come in handy for another vbulletin forum I browse, which only allows in-site hotlinking (we have a gallery); if I had the actual URLs of attachments, I could re-use images attached if I needed (unlike Wilder's, the fake URL does not work for hotlinking on this website).

 

Wow, interesting. Thanks!