You must first create a Differences window and a Zoom window using and .
The Scan command on the Differences menu automates zoom mode and causes the bitmap tool to scan for differences from left to right and top to bottom. When the first difference is found, a small square, 32 x 32 pixels, is shown in the Baseline Bitmap, Result Bitmap, and Differences Bitmap windows in the same relative location. In addition, that location is shown in all three panes in the Zoom window.