Another new feature for Containers and Columns in Avada 7.0 is Responsive Option Sets. You can see the Responsive Icons at the top right in the below image of the Container Element. Just note, that this feature is only available on the new Flexbox Containers, and not on Legacy Containers.
Please see the Responsive Option Sets documentation for specific details of this awesome new feature, but in short, it allows you to change what screen size you want certain option values to be valid for, and allows you to have up to three individual option sets for the included options. You will also see a screen icon on the individual options that are a part of this feature. A simple example of how this feature might be used would be to enable different container margins or column widths on mobile view, as opposed to the tablet or desktop view.