I've added photos to point, and used the JSON editor to make them optional, but it looks as if photo capture is only possible for points, not polygons or lines....
On a polygon or a line button, the camera option is not available. I tried to edit the JSON to change the cameraInfo mode to manual and "required" to false - which added the camera icon on the button in the designer, but the camera is not available when I open the app.
I did enable attachments for the lines and poly's and enabled editing and sync.....