css-animations/animation-direction/reverse

SakerONE

#div {
position: absolute; top: 50px;
width: 100px; height: 100px; background: blue;
    -webkit-animation-name: shift;
    -webkit-animation-duration: 10s;
    -webkit-animation-iteration-count: 2;
    -webkit-animation-direction: reverse;
  }
 @-webkit-keyframes shift{
    from{
        top: 50px;
        left: 0px;    
    }
    20% {
        top: 150px;
        left: 100px;
    }
    to {
        top: 400px;
        left: 300px;
    }   
 }

http://jsfiddle.net/uVv65/2/
why do the reverse animation-direction is the same as normal? I thought it would go from

top: 400px;
left: 300px;

to

top: 50px;
left: 0px;