Select an image - either from a web page or by uploading a file - and the extension will show a preview how the image will appear as an Opera browser theme.
Choose either a best fit or tiled image, and select a tint color for the browser chrome. You can then try out the theme on your browser, or download it as a zip file and submit it online.
Important - please refresh your browser after installing the extension for the very first time, to avoid any problems displaying images. Image upload will not work while on the speeddial page.