What are photos for?
In the Menu section, there's a hint about whether your restaurant's menu has enough photos. You can see how many photos you've uploaded and how many you still need to add to make the menu more effective. You can also view photo status next to every item: if images have been uploaded, which are still under moderation, if there are any issues, and how to resolve them.
If more than 80% of menu items have photos, users are more likely to choose them and you're more likely to receive orders. Photos attract user attention to delicious food, show portion size clearly, and help users make choices.
If you want to take the photos yourself, read the article about how to photograph items on your phone.