I'm thinking that if there were really fold outs, the top would be an Art quilt and not a Use quilt. I've seen many people exploring the concepts of "quilts" of being layers or having secrets inside. I remember one quilt in a museum show that had organic elements like coffee grounds or things that would rot/discolor the project. (LOL sometimes maybe there are things you wish you could forget). I would concentrate searches with suitable phrases.
The thing about secret messages is often they are secret... 2020 was a hard year on me in many ways. One of the happier things was I worked on the Bonnie Hunter Frolic project. Mine, other than fabric choice, was exactly Bonnie's design. Later in the year as I was struggling, I completed another board member's project that got abandoned mid-project. Her fabrics are more standard. I completed the project as something to do and that I didn't want to be responsible for getting it quilted down and sent it back to the starter.
There is a secret message in the completed top which I did share with the recipient and I feel almost bad for sharing here -- I did the borders differently. The message is "red white and blue, we are stronger together". The geese seem to go around the edges in a weird way, well no, they are all coming from one corner and going to the other, together.
My top is first, with the split/divisive as designed border. I debated between the geese shapes and movement, or making squares/kites in the second top as being more "unified" but they looked clunky -- maybe just with the after vision of my top in my eyes.