Balance?

Dinnertime today I was wandering around in between the almost unremitting rain looking for pictures, when this military helicopter flew over, did a complete circuit and then flew off. I snapped a picture, 'cos that's what I do. When I later came to look at it the first thing I thought was 'just missed the sweet spot' - a few seconds earlier the helicoper and the tower block would have balanced in the frame. Usually I'd dismiss the picture, but something pulled me back. I still don't know what it is; maybe the tension in an unbalanced image, maybe because I feel it's a story unresolved? Of course that could all be complete bull, but all I know for sure is that for some reason I like it.