right, biometric identification for targeted advertising, plus I'm gonna predict a touch of algorithmically automated body-shaming
"Amazon Studies Body Sizes to Get That Perfect Clothing Fit
The online retail giant is inviting people to New York to measure them with a 3-D body scanner"
https://www.wsj.com/articles/amazon-studies-body-sizes-to-get-that-perfect-clothing-fit-1525355115