The latest big Cozy Grove update just got pushed out to Steam and, I believe, other platforms. It comes with a camera that lets you take photos of the island and some new non-storyline quests which involve taking photos of specific things.
You buy the camera from Mr Kit. The camera description says you need to buy film from Mr Kit then use Jeremy Gruffle's craft bench to put the film in the camera. The camera comes with film in it, so you don't need to do that right away.
To take a photo, put the camera in your hand (go to your backpack, highlight the camera, and press A). It's the next step that took me a while and is the reason for making this post. To take a photo, hit the shoulder buttons. I think it's the lower left one. You'll see the shape of the photo appear on screen, and then you can move it around and press 'A' when you're ready to take a shot. It then lets you decide whether to keep it or not. I can't find anywhere in the game that tells you what you actually need to press to take a photo, so I spend ages pressing different buttons and trying things around Jeremy Gruffle to see if a lack of film was the problem.
