Amazon calculates a product's star ratings based on a machine learned model instead of a raw data average. The model takes into account factors including the age of a rating, whether the ratings are from verified purchasers and factors that establish reviewer trustworthiness.
The rainbow colours that you see in the photo, please do not expect the product to be like that when you receive it. The top looks dull. And the size Small looks like Medium size so heads up on that. Extremely thankful for Amazon service for taking all the cares of refunding me the exact amount after returning the product.