It is a small box with a grid pattern in the vertical and horizontal directions.
There is no mechanism that seems to be a gimmick, but where will it open?
Or is it just a mass of wood that doesn't open?

block-C and block-R, open in a similar way.
C is a cube, making it difficult to tell which side will open.
R is a rectangular cuboid, and the main point is how to hold it when opening it.