1. Once 100% Image Alignment is done, click on "Select Bounding Box"   icon on the left sidebar.

2. A box wireframe surrounding the sparse points will appear automatically in 3D window.

3. In 3D window, adjust the red colour 3D box such that object is completely and tightly enclosed in it using "Box Mode" icon on the top toolbar.

4. Once you are satisfied, click on "thumbs up"   icon given below 3D window. This will submit the image.

Watch complete process video below for more details.