I would say that while #1 is a good shot, its impact is diluted by a few things. First off, the background: the yellow play equipment inside the play structure, and the square behind on the wall, as well as the kid's black, detail-less hair all work against maximumj impact. The boy is seen inside a play structure, but the eye also has PLENTY to look at off to the left and behind, and his dark hair, with no detail in it, removes focus on the child. "Light advances, dark recedes" in hundreds of years old. The highlight on the yellow play toy (looks like a toy front-end loader!), the highlight on the window square behinds him; the crack in the wood causing a bright highlight to sprout out of his head; overall, the first photo has TWO, distinct depth planes, and a number of small but critical distractions in it, such as the knot I mentioned. If you count them up, the first shot deals with four depth planes.
The third image has a kid with lighter hair. Light advances, dark recedes. The third shot has the flat plane of the structure, then the child shown peeking out, face in one "pane", active, raised arm in another "pane"; the first has distractions, and depth BEHIND the main subject. The third shot of the girl has the front plane, and BOOM--the child is the SOLE FOCUS of the shot, with nothing visible and nothing distracting the eye, behind her!
This is how I analyze photos. This is the type of dispassionate thinking I've learned to apply to photos, breaking down why some work better than others. If you clone out the discolored spot on photo #3, it will be even more unified.
#2 has a background that distracts, and does not help. The second shot has a cluttery backdrop.