[burntoutfire]

How can he get that from just a photo?

[heavyset_go]

From firms like this[1].

[1] https://www.vice.com/en/article/5dmkyq/heres-the-file-clearv...

[kevin_thibedeau]

You collect cell phone IMEIs and sell it to a data broker that aggregates multiple sources to pinpoint strong associations that lead back to a shopper's home. In return you get demographic data on your customers.