JB
An interesting image. My first thought was the softness but I see you've already mentioned it. I wonder if sharpness was lost when you downsized it. You might try to crop from the bottom and make this into a pano. I've done a quick crop to show you what I mean.
An 800 pixel image across, saved at 51kb, will have noticeable jpeg anomalies that will affect the overall IQ. I would try downsizing again, but when you save the jpeg, adjust the jpeg compression such that your file size is as close to 200kb as you can get but still under. I find that on average, a jpeg compression of 9-11 will produce this.