Make that "Someone" a Movie Clip named "Someone1". Make a keyframe on the frame you want the zoom to begin. Then make a keyframe on the frame you want the zoom to end (keyframe 2). In keyframe 2, enlarge Someone1 with the free transform tool. Then create a motion tween between keyframe 1 and 2.
Practice with a circle or something on a blank document until you get the hang of it. You can increase the speed of the zoom with the "Ease" tool.
I'm pretty sure thats how it's done.