Isn't this the same situation with having the king and joker unobstructed on the same orthogonal? This pins all rooks, queens, chancellors and so on.
No, this is different: moving a pinned piece is something the opponent punishes in his own turn, by capturing the King. The question here is whether the side that moved has delivered check with this move. Even when he does, he cannot capture the King. Because it is not his turn.
Anyway, the Diagram considers this stalemate, because the Imitator moves like a Knight. This is how I defined the I atom in XBetza:
A new atom in XBetza is I. Unlike the other atoms, it does not represent a fixed move: it stands for "all moves of the most recently moved (or imitated) piece type".
The most-recently moved piece is a Knight here. It doesn't say anywhere that the piece has to be an opponent. In your own turn it would of course be one. So this doesn't affect how the Joker moves. Just how it delivers check (which again is only important in the case of mate or castling).
No, this is different: moving a pinned piece is something the opponent punishes in his own turn, by capturing the King. The question here is whether the side that moved has delivered check with this move. Even when he does, he cannot capture the King. Because it is not his turn.
Anyway, the Diagram considers this stalemate, because the Imitator moves like a Knight. This is how I defined the I atom in XBetza:
The most-recently moved piece is a Knight here. It doesn't say anywhere that the piece has to be an opponent. In your own turn it would of course be one. So this doesn't affect how the Joker moves. Just how it delivers check (which again is only important in the case of mate or castling).