This snippet holds custom HTML code for full-screen background. Once the page is shown, it will show html/Welcome.png image in full-screen mode.
html/Welcome.png file is a symbolic link to files/Welcome.png, therefore you can use HTTP file/put command to replace files/Welcome.png with any image of your choice.
This text shall not be visible once the form is displayed. If you see this text, most likely no image at files/Welcome.png path exists.