It’s not a bad shot at all. Colors are nice, composition is interesting. It might be a touch underexposed, but if you’re trying to sell dusk then that may not be a bad thing. The only time of day the sky looks like that is going to be sunset or sunrise, so I think your colors are mostly OK. A little bit on the cool side maybe, but that’s probably fine.

Now, is it the feeling of a sunset? No, not really. There’s nothing in the picture that conveys that feeling. You do have some interesting things going on – humans dwarfed by massive architecture, antiquity contrasted with people on their cellphones, a couple of interesting little vignettes in each cluster of people – but none of this says “sunset” to me. I think the image would be almost as effective if it was broad daylight, albeit a broad daylight with soft diffuse lighting. In other words, if you took “sunset” out of the image you wouldn’t lose much, except for the very pleasant background gradient.

But even if you didn’t hit what you were aiming at, I think that this is overall a fairly successful image. If I took it, I would be very happy with it.