Many congratulations, Peter. There's a warmth, a sensuality and an air of mystery in your photo which tells (or, more accurately, suggests) a story. I've looked through the others several times and there is some good photography but very few of the photos actually engage me for more than a few seconds.
I have no formal art education so I risk being called a Philistine, however, your's is one of the few shots I'd look at repeatedly and fine something new and interesting. The rest are good record shots. I agree with Becky - you should have won the prize.