An unusual whimsy, and a bit of a mysterious one, with just these little diamond shaped windows revealing the pointed tips of the form inside, which does seems free from the "cage" but forever tightly trapped! Quite a compelling little carving, I think, and a nice addition to a whimsey collection.
I believe this is quite an old one, perhaps late 19th or very early 20th c. There is a bit of hairline cracking on two adjacent sides, not visible depending on how one positions it, and a tiny old nick to one corner. Otherwise, in very good shape, with a great patina. Approx 1 1/2" tall, wide and deep.