Such a long poneytail is a feature not often seen. Only some countries carry one : Austria, Madagascar and also Poland where it's about the only nice thing that did survive the extreme iconizing process.

Now let your eye wander down to the legs of the boy. Isn't there something peculiar? The thigh is more slender than the rest of the leg. The more you look at it, the more it gets unrealistic. I'm also not happy with the front leg of the girl. I know that she is running and that her skirt is probably more fit for walking, but even then. The insertion of her leg looks unreal in my opinion.