To expand a little on previous answer. At home screen on dashboard, select "Upload, Add Images" button. Type in a new name and select "Terrain" of "Structures" option. The click "Select Images" button and select the same group of images previously submitted. Once you select the images it will display a rectangular boundary for your map area that you can tweak in the normal fashion. It will also show the usual options for GCP's, speed vs quality, etc.