The silhouette effect is interesting, but for my taste (very subjective) I find that the large mass of pure black with no detail in the 2nd and 3rd image does not add to the quality of the pictures. If the outline of the top of the black produces an interesting shape against the color, I would either crop out the larger lower portion of the images, or, more preferably in the shooting I would move in a bit more for the same effect.
In the top picture, the pure black shape seems better integrated into the image and works better for me.