I am a lead software scientist in the Facial Recognition industry. Amazon's ‘Rekognition’ service is a sad, expensive joke. No body takes that software serious. It is poor quality. It is expensive. It is marketed to the consumer public for Amazon's stock, not for actual serious FR use. It is not appropriate for any serious FR use. It's a toy.
I'll say that again for those in the back: it's a TOY, expensive and hardly works.