This is the one rule we can draw but never replay: the feed records the call and the restart, never the crossing. So in a real game, watch the line rather than the play.
The puck carrier comes up the ice toward the blue line.
A teammate crosses the line before the puck does — that is offside. The puck has to cross the line completely first: touching it is not being in the zone.
Play stops, and the face-off comes back outside the zone.