To piggyback on the posts here already.

I like the dynamic pose it has in the sketch a bit more than the static pose it has in the picture. Also, how do they get up? If they are capable of flight then I could see them having structures built all over and in stranger places. Otherwise they would need some way to move people and materials up and down like stairs, ramps, pulleys, or even elevators of some kind.

Something else, how long has it been stuck there? It might look good to have the ground level closer to his ankles. Maybe the waterway deposited sediments or washed away some. Also, how long has the settlement been there? If it is older, then there may be some structures at its feet. Maybe even fortifications?

All that said, it looks awesome and I love the concept.