Sorry to pick this only from the whole analysis, but i'm 99,99% sure this chess piece is not a Bishop. Played on hundreds of chess-sets in my life, not a single one had a Bishop that resembles to piece that is painted. Also played on many chess-sets that had Queen exactly like that. It's a bit non-standard look of the Queen piece, nevertheless some luxury sets have Queen with the collar like that. Bishop is always rounded in that area.

This is important because if that Queen-Knight (Elisabeth and her lover) allegory is true as some suggest, this board may have nothing to do with the chess board and Yari Shogi, it is just used as a mask for real meaning of what is painted. It further implicates if that is not a chess or Yari Shogi board, it gives fuel to the observations that vines and leaves always start in the cracks, between the fields in the board, and that center of the keyhole is exactly in the crack. If it is not a chess board maybe it should be read completely different. That's why it is important that the piece is not a Bishop. A little blasphemy for the end: let's just assume for a second there is 1% chance that rabbit character is not complete troll (I know, hard to believe, but let's give it 1% chance he knows something). In that case his hint with Michael Jackson's YouTube clip - "It don't matter if you're black or white" maybe means it doesn't matter if the fields on the board are black or white because it is not a chess board.