Thank you for reaching out to the Community! I apologize that you are unable to see your photos in preview or when you send a test. Can you please try to drag the images from the Images tab into the editor below the image that is not displaying in preview to see if your image will display like that instead. If that doesn't work, please Insert the images via URL and let us know if that fixes this. When you insert an image into the editor, you can left click on it and select replace, then you see the option for Image URL. An example of what this looks like is the screenshot provided below. Thank you!