I feel like it's more poetic than that, it seems like he's looking at someone, possibly the person hanging out the window, as if they're saying goodbye, running along beside the train, looking at this person for what might be the last time if this train is bound for rosslare. To take it even further he's sprinting in a last ditch attempt at confessing his love before she leaves to work in the UK. He knows he's got one last chance, and this is it so he sprints, frantically shouting out over the sound of the engines before he runs out of platform and the train goes out of sight. He's left standing there, out of breath and on the platform edge, not knowing if she heard him or not, but knowing he'll have to wait at the station for the rest of the day, watching every train arrive, hoping and praying she's on it.
Got a bit carried away there, probably just the wrong platform.