Groom will not bleed down into the spine

This 2-page spread was created in Adobe InDesign (setup as facing pages), then converted to PDF. Creator started with one image that was stretched across the entire spread covering both left and right pages. He then placed the image exactly where he wanted it to be. Then he made a copy of it. Then he cut both in half so that one became the left half of the image and the other became the right half of the image.