You can really do any design you want. The key is to not cut all the way through the wood so that the epoxy fills up the holes. If a section does cut all the way through, it’s ok, just cover the back with masking tape. All kinds of wood work too, I haven’t used plywood because I wouldn’t want to sand through the layers. I’m sure with some precision it can be done though.
If you want you can do 4 designs and have 4 sides light up. There are so many possibilities. Use your imagination. The video of this light from start to finish can be seen here.