To set properties for an image placeholder, select the placeholder in the Document window; then select Window > Properties to display the Property inspector. To see all properties, click the expander arrow in the lower-right corner.
Use the Property inspector to set a name, width, height, image source, alternate text description, alignment and color for a placeholder image.
In the placeholder Property inspector, the gray text box and the Align text box are disabled. You can set these properties in the image Property inspector when you replace the placeholder with an image.