One file in from the edge, the defender's king has nowhere to hide: it is forced to a7 or c7, the attacking king approaches with tempo, and the pawn promotes.
This is the b-pawn version of the previous position and the evaluation flips completely. The knight on d6 protects b7, and the black king on b8 must move. Its squares are a7 and c7; a8 and c8 are covered by the pawn. From a7 or c7 the king still attacks the pawn, but White's king is free to approach on the opposite side from the black king, and there is no stalemate trap because the black king always has an escape square on the seventh rank.