How to make a fabric dollhouse

My daughter was gifted a toy like this, it's a birdhouse and there's a hold in the roof to put the birdies in and a see-through plastic side door and window for little hands to take the birdies out. The side also drops down. I think it's the cutest.

I love this barn but think that a 2 dimensional felt scene on the back & side walls (hay bales & a chicken in the rafters, a tractor?) would enhance the play experience. Complete instructions are here.