1and1 CDN Clear Cache and Developer Mode

There are more settings to be played with in 1and1 control panel they just aren't easily found.

1. Log in to your control panel.
2. From the home screen, scroll down to the "MANAGE WEBSPACE" section.
3. Click the "More >>" link.
4. Find the "Content Delivery Network" section.
5. Click "Open".
6. Select the domain using the CDN.
7. From the "Edit" dropdown, select "All Settings".
8. I am not sure if this is required, but it won't hurt anything.
   1. under the general settings...
   2. Click "Edit".
   3. Turn on Development Mode.
   4. Click "Save".
9. Rollout the "Performance" section.
10. Click "Edit".
11. Here you will find an option to "Purge Cache".
12. Your images should be updated. 
13. Make sure to turn Development Mode back off.

There are a bunch of other options available here. Make sure you read up on them before pushing buttons. :D