You can include a picture to the Confirmation Messages.
1. Upload the picture file:
- in your website, and make sure it is accessible, for example from a link similar to http://www.yoursite.com/image.jpg, or
- use a website where you can host images for free - for example, https://postimage.org
2. In the Description field of the Confirmation Message, click on the HTML button
3. Type: <img src="http://www.yoursite.com/image.jpg" width="200" height="100"/> (replace 200 and 100 with the correct dimensions of your image. Please note specifying dimensions is important for the correct resizing of the widget page).
4. Click on Update