AWS Rekognition doesn't seem to work with video.
For what I could trace, this might be due to storyboard image size.
From AWS faq :
although Amazon Rekognition accepts images that are at least 80 pixels in both dimensions.
And default storyboard size is 100x62, so if there is no contribution changing this size, AWS wont work and result in error.
Note for Pictures
If pictures have less than 80 pixels in any dimension, it will result in :
User isn't warned that recognition has failed.