photo rejected at Shutterstock

[kevin99989]

Hi !
I just had a photo (out of a few) rejected at shutterstock. This is it. The reason was "Poor Lighting--Poor or uneven lighting, or shadows. White balance may be incorrect.". This image has some dark spots that naturally occur in the image - i'm wondering which specific spots in the image they are referring to (the uneven or dark shadows)??

Thanks for your help!