A person who takes a picture of every single meal he/she eats and posts it on a social media, usually Instagram.
"Of all the types of people who use Instagram, the Food Photographer is probably the most bizarre."
A person(s) who takes a photo of their entrée at dinner at a restaurant before they eat it and posts it to social media. Generally the person makes everyone else wait until they take their photo to eat.
Jill: Beth can we eat yet, we are hungry?
Beth: wait, I gotta get a photo of my steak dinner for my insta.
Jill: you're such an annoying food photographer, no one cares!