Does a derivative work become hidden if the original author hides the source image?
No, the derivative remains in the public. Simply put, once it’s been given out, it can’t be taken back. Here’s a real world analogy: If you lend your friend a CD and then ask him for it back a day later to destroy it, it doesn’t change the fact that your friend may have already made a copy of the CD that will continue to exist no matter what you do to the original.
