The image above is hosted on IMGUR.COM. You can tell because the url is "http://i.imgur.com/Msv8eHpl.jpg"
Your second link is to DropBox. You may think that file is local to your computer, but it is also stored on the cloud where it is accessible to other users. DropBox automatically synchronizes the cloud folder and your local folder, but the link shared on RV.NET is actually hosted on the cloud.
So, you may believe that the images are local to your computer, but they are not.
Try this test. Turn your computer completely off. That way, the images on your computer are not available to be displayed. Now, use another device to look at your pictures on RV.NET. If you can still see them, they are hosted on the cloud, somewhere.
If you click on the DropBox link, it actually says on the upload screen "Photos hosted by IMGUR.com" That means your photos are being uploaded to IMGUR.COM and linked to RV.NET from there.