Change file icon OS X

I tried following Apple's instruction to change a file icon but it didn't work they way I expected...

Details:

File type: "web internet location" or Inbox.webloc

So This it what I've tried so far:

^ Right click "Get Info"

Copied the icon file

And... pasted

Result:

Not what I expected... Am I missing something? How do I change this file icon without using apple script?