It's a giant chess set and two players are on the squares placing a few pieces.
They placed the kings, and each placed a pawn. One of them had placed a pawn on a promoting square, so the pawn was immediately promoted to a Queen. Each made a move and the game was over with a checkmate.
The total on the squares are 2 players + 2 Kings + 1 pawn + 1 Queen =
6 on the squares, of the chessboard.
[FEN "8/6Pp/8/7k/5K2/8/8/8 w - -"]
1. g8=Q h6 2. Kf5 Kh4 3. Qg4#
lichess.org/analysis/standard/6P1/7p/8/7k/5K2/8/8/8_w_-_-