Full width image in boxed theme style

I have the Pro version of Newsup with a boxed theme style, but I see other sites that are also boxed that have the ability to add an image here or there that is full width. Please see the website https://www.allrecipes.com and scroll down where you can see the images that span all the way across the screen but the main style of the rest of the site is boxed. I cant seem to find any plugins, widgets or theme options that will do this.

So do they just have the site set to full width and then have other certain sections boxed? or how it is achieved, and what is possible to have this sort of look and layout with Newsup?

Thanks!