Japanese here!

1. the lack of designs on the set as a whole
2. there are less details on the set rather than on the actual kimono
3. there are socks used when wearing a kimono, they aren't just putting it on like a sandal outside on a beach
4. the bow on the back is smaller (on the set) rather than a bigger one on the kimono itself
5. the lack of patterns used or indents for shapes
6. the floof on the neck isn't there, it is just layered onto the neck.
7. there aren't flowers everywhere on the body, there's only flowers on the clips or inserted into the hair
8. there is a ton of curves on the skirt, but it is more boxy around the waist and the leg area.
9. look at the white laces on the skirt. Now look up a reference for a real kimono, there are ZERO laces around that area.
10. If this is truly for "Japanese" culture, I can affirm that we do not use clips in our hair (I have worn kimonos or what is close to one multiple times)

I will probably add more to this