This was terribly disappointing to me. It's basically just showcasing that tmux can be an 8x8 grid of panes.
What needs to be done is building a project that can "move" pieces from one square to another, according to the rules of chess.
At the very least, use Unicode chess pieces[1] instead of typing "black pawn" everywhere.
[1]: https://en.wikipedia.org/wiki/Chess_symbols_in_Unicode