You can post photos from Facebook, but it's a little tricky. To post a photo from Facebook, right-click on the photo. If you have an option to copy image address, do that. That's the easiest way. If you don't have that option, then go to the Properties and find the image address that way. It should end in something like: .jpg, .jpeg, .png, etc. If it doesn't, it's not going to work.
Hope this helps!