This Page details how Administrators can change their own Picture which appears on the Staff Page.
How to
Simply upload an image of your choice in PNG format with the name YOURUSERNAME_Pic.png and the image will automatically overwrite the existing one. No changes to the staff page will be necessary, but the page will need to be 'purged' in order for you to see the changes.
To purge any page, simply add ?action=purge to the end of the URL which will force the page to load the latest version without relying on your browser's cache.
Your chosen image should be 523 x 471 or keep the same aspect ratio to appear the same size as the other staff pictures.