Sometimes, the images just dont fit like you want them to. Here is how you can select the image, without the mask, and move/resize the image.
Select the image that you would like to move/resize. By default, the layer will be locked to the mask so you can only move the entire box(both image & mask).
Click adjust image, this will unlock the image from the opening.
You can move your image around in the mask.
You can resize your image in the mask too. After adjutments hit the return key (enter).
NOTE: IF YOU INCREASE YOUR IMAGE MORE THAN 20% IN SIZE WE RECOMMEND REFILLING THE IMAGE AFTER THE ADJUSTMENT, LIKE THIS.
Hit the "relock" button to relock the image and the mask.