Images Stuck On Server

I've run into a strange problem with images being "stuck" on the server.

The problem began when I uploaded an updated picture via FTP (I use Cyberduck for Mac) to override the picture. This didn't work, the picture wasn't overridden at all. So, I tried deleting the picture from the server, but it wasn't removed. I cleared the cache, tried different browsers, but the image at the given absolute URL just never disappeared. But, using 2 different FTP clients, the image is shown to not be there. I used the file manager provided with cpanel as well, which also showed the directory empty.

I then experimented and deleted the entire folder of pictures with FTP, but the entire set of pictures was still accessible online, but shown as empty.

I'm confused how there can be an absolute URL of pictures that works, even when FTP shows it as empty.

For example, from my index.html file, the path to pictures is img/team, which is full of 10 portraits of team members. I deleted all of the 10 jpg pictures, and even the entire team folder.

http://ift.tt/1RSAc6u when loaded in browser doesn't load, 404 not found http://ift.tt/1GF5dim does load, this is picture "stuck on server"

How can an individual file be accessible, when the folder containing that file isn't? Is there a way to investigate files on server that FTP clients can't "see" for some reason?

Thank you for any help.