I agree the tattoo should have been photoshopped away.
Personally, I think the hair should be more yellow rather than brownish and longer.
This is actually very important because when you look at the picture of Oshino, her striking yellow hair stood out and becomes a point of focus and also a point where you rest your eyes on, but in the cosplay, our eyes rests on her clothes because the color of the hair is too muted to stand out.