The new terminal at Carlisle is absolutely nothing like the terminal at Southend, there is absolutely no comparison :-)
There are images online a simple Google search will show you images.
It's basically within an office building as in the Stobart HQ with a very small passenger terminal incorporated on part of the ground floor and as others have mentioned it's only big enough to handle about 50 passengers so it's definitely not a 'miniature version' of the Southend terminal in any form.