Where is the safe and how can I open it?

Hint 1 of 3:

There is a safe behind the picture.

Hint 2 of 3:

Click on the picture to reveal the safe.

Hint 3 of 3:

You will have to figure out the puzzle without any hints because there
doesn't seem to be any solid answer to it.  Just keep on moving the pieces
around.  You will probably have to reset the puzzle from time to time.  You
can usually finish the puzzle in less than 10-20 moves.