The Switch Product Layout provides the ability to create multiple product page layouts in the Web Builder, and assign them to different products on the product edit page.
Creating different layouts provides the ability to showcase your products in the most effective way. For example, you may want to display some products with a large default image, and some with a small image and a lot of details. With this module it is simply a matter of setting up different layouts and assigning them on the product editing page. No coding required.
A good example of this is the Gahela Themes are displayed with a large preview image, and the modules/extensions have a more traditional layout.