The Container (Campaign background)

The 'Container' refers to the box in your Engage, Amplify and Capture campaign builder where you enter your campaign elements ('widgets') 

The existing 'container' size is locked to 622/956 as a 'safe zone' - during testing we discovered that larger sizes of container were incompatible with some viewing screen sizes, whilst the 622/956 works on absolutely any screen....

You can still move items outside of the container by clicking on and using the arrow keys, and the visible result will be the same as if they were inside the container (except, if the screen size is incompatible with the larger size) - And if you want a smaller overlay, just remove any background from the container and just the 'elements' will appear to the viewer