The last thing you need to do is assign a script to the movie clip itself so that when you click on it, it jumps ahead to the next frame in the timeline and plays down to the end, animating the image shrinking out of sight again. Right-click on the Actions panel and insert the following:
on (release){
this.gotoAndPlay(7);
}
Naturally the frame number it jumps to will change depending on your animation.
All you need to do now is repeat the entire process for each image in your gallery, and youre done. You can play with a working version here.