When a Zoomify file is added to a screen, the tool gives you the option to add an overlay (graphic(s) that appear over layers). As long as the file is formatted with a transparency (.png), you can add an overlay to the default image. Overlays can be used to add details, icons or other components.

With the overlay populated, the preview shows the default image with the overlay option(s) along the bottom left. Once an option is clicked, that overlay appears over top of the default image (see examples below). Note: Overlay buttons are toggles - they can be turned on and off so multiple overlays can be viewed simultaneously. A green checkmark indicates that this overlays is currently "on".