make sure you add a GB Image Block ( not the core one ).
Add the block to the page, and set it up for your Desktop.
Then change the Preview to Mobile, and you can use the Width and Height fields to resize the image
So as long as your Inner Container is wider then the Mobile screen the it will be full width.
You just may need to remove the Padding from the Container Block. Again you can do that just for mobile when Previewing it.
Thanks for that. Is there any way to keep all the bullet points aligned on the left hand side? Would that need to be done with margin rather than center aligned?