It's a stock photo, you're reading into it too much. I doubt the guy went on a date and then asked the gal to strike a pose: "I'm writing an article about how I'm dating 150 girls, can you please pose for a photograph?"
He did online dating, meaning all the girls had already published their photos in the internet before he met them. Just right click and "Save as" would do the trick, if he really wanted to include real photos in the article :)
But yes, I also think that's a stock photo.