I've successfully built LOS from source!: https://lisalist2.com/index.php/topic,644.0.html
Is is common for the marketing or documentation folks to be out of sync with the products they are promoting, many times they have the task of creating materials for a product that is not completed ahead of a product launch. Because of this, many screen-shots are mock-ups due to the product not being finalized at the time. For all we know this is a image of a Mac screen that was superimposed on a Lisa photo.