About using graphql api to change product pictures

[huirao]

Hi, I am using the productImageUpdate API to change the product image, but when I upload an image with a transparent background, the interface returns me an image with a black background after the execution is successful. What is the reason?

This is my transparent background image：

https://deeplor.s3.us-west-2.amazonaws.com/matting/2021/03/06/1b09a0cdc3df417bad14751219f008bd.png?X... 

This is the image returned to me after the request is successfully executed：

https://cdn.shopify.com/s/files/1/0535/6050/8611/products/4.jpg?v=1615016961 

This is the statement I executed the request：