Each of the models analyzes a different aspect of the media.

Metadata will look for any metadata anomalies that may indicate editing or tampering.
Provenance looks for traces left behind in the file by many photo editors.
Integrity evaluates whether the file structure is valid.
Photo of photo looks at whether the image may be a photo of a screen.
Quality determines if the file has potentially been modified to hide detail by lowering the quality.
Reverse Search looks for matches of the image on the internet potentially indicating the image is not original and has been downloaded.