Some small frames tend to lean too far forward when hung. To remedy this, first check that the wire or cord on the frame is not either too slack or fitted too low. It should not be more than one third of the way from the top.
If the frame still leans too far forward, tension the hanger by holding down the bottom end and pulling down. If the frame straightens up as you pull, the Tensioning Weight will have the same effect. Just hang one on the bottom hook. It will be hidden behind the picture on that hook.