Lovely sunset. I assume you used Glow on the Swans? I like the look a lot. I wonder if including more of the second swan might make it looks better to me.
With 1 1/2 swans in the left half and nothing in the sky in the right half makes this somewhat unbalanced for me. So maybe just 1 whole swan for this presentation. Having that 1/2 swan with the long neck coming in is interesting in our OOTB way so maybe you want to play with this!
I'm going to pretty much echo what's already been said. I'd be inclined, I think, to crop from the right for more balance. As for the second swan, I'd lower it to get away from the straight line and maybe tilt it up just a bit. A third swan (the head and just a little of the neck) above the second one but below the wing tips of the first one would not only give three instead of two but would read better, I think.
3 heads are better than 2, although I would make them all level with the horizon. Angled as they are makes them look like they might crash with swan 1, in Angry Birds fashion !
I love the sunset and the treatment of the swans. I prefer Dennis' addition of a third bird, and the crop from the right...it does appear more balanced now.