Now you have a nice, masked image with nowhere to go. Let's send Meagan to Hawaii to see how our mask looks there.
Open the image you want to move the masked image to (in this case the picture of a Hawaiian beach). Make sure both windows are partially visible. Move the masked image onto the Hawaii image by dragging it with the Move Tool.
In this case, the 300 dpi masked image covers the whole 72 dpi Hawaii image and then some. Make it smaller by pressing command-T (Edit>Free Transform), a bounding box appears. Pulling on the handles distorts the image just like the Crop Tool. To get a proportional scale down of the image, press the shift key while dragging one of the corner boxes toward the center. When the desired size is reached hit Return to commit the changes.