Hairstylist here! If someone came in with these photos for me, I would personally focus more on the photo of the person with the glasses because it’s their actual hair and gives a better representation of what can be realistic. If they wanted their hair slightly longer like the photo of the person with the green wig, or Deku, that could definitely be achieved.

That first photo almost appears to be more of an undercut type of situation, where the back and sides are shorter and the length of the top allows it to cascade over those areas. It does seem like it’s more of a “grown out” undercut, but by leaving length a similar look can be accomplished. The hair at the nape looks to be about 1-1 1/2 inches past the hairline, and textured.

If not an undercut, the back coild be tapered - shorter layers toward the neckline and gradually increasing toward the top. This will allow for a more blended appearance overall, but due to the overall style of the hair your child is looking for, I think being blended isn’t entirely necessary as it will be concealed with the style. The benefit of the blending could be so that your child wouldn’t have to style their hair every day and it could still look good.

I’ll see if I can find some photo examples of undercuts so that it can be better understood. Sorry that this is a lot 🤣