"Created by" means I got the icon from the credited source (or I admit to finding it someplace).
"From" means I got the image from the credited source (or I admit to finding it someplace), but created the icon myself
Just a source description, means I took the photo and created the icon myself.
Edit: Forgot to add... You'll be seeing more of them, as the latest version of the Semagic client can auto-rotate the usericons used with each post. You can find links to the latest version here.