@Kylian Artefato, the edges of the cut aren't smooth and there is some snow in the hair. Moreover, cuts should be in 250x250 (if the source is large enough, like it seems to be here) or in 180x180 (if the source is smaller). Cuts should also be as upright as possible, not slanting to one side.

If you want to improve your cutting technique and to produce cuts which are of sufficient quality to be added to the megapack, read the guidelines in this thread and watch the video tutorials. Otherwise, it's best to provide the source and let us cut it for you 😉