Description:
EtsyError: Failed to send listing image '...'. Does the image exceed maximum allowed size (10MB)?
This means the image you were trying to upload exceeded Etsy's maximum image size of 10MB. The URL will be listed instead of '...' to help you identify which image is too big.
Solution:
Reduce the size of your image or use a smaller image. There is no way around the maximum size limit through Shop Uploader for it is set by Etsy.