Use the select visible layer control 
to select what information is overlaid on the step image. You have the following options:
- Diffs
- If you select this option, then pixels where significant differences were found are colored pink.
- Remarks & Issues
- Select this option to display remarks and issues added by the user.
- Regions
- Select this option to display match level regions added by the user.
- Viewport
- Select this option to add a boundary box that represents the viewport size relative to the image size (relevant when the image is large than the viewport size).