Special Effects Editing - Making a Character Giant

The Tutorial:

My Edit:

I put the clip of the stage into the sequence editing area. Then, I used "effect controls", and within "opacity", used the "free draw bezier" tool to select the area inside the stage, and inverted this. I then selected "nest", and moved this clip up to layer 2. Then, I added the clip of William to the sequence on layer 1, and this clip "nested" itself inside the nest on layer 2. Finally, I scaled the clip so that the edges of the box fit the size of the edges of the stage.