Imagine this scenario: you chose what you thought was a perfect picture. So you insert the picture, and then enhance it using the cool picture editing options available in PowerPoint 2011 for Mac. You may have gone further — for example, you could have applied some of the Adjust Picture options, added a border, applied some Picture Effects, etc. You went ahead and added a perfect combination of both the Fade and Zoom animations, and also timed it to happen at the speed you want. And then you discover a better picture, or your boss asked you to change to another picture. You also need to retain all the effects and animations! You could delete the original picture and start all over again, and yes, that is a long process! Or you can change any existing picture into another with just a couple of clicks.