The phone will switch depending on conditions.
If conditions are good, it will use the zoom camera. If not, it resorts to a cropped view but may use info from the other sensor to enhance the image via processing.
The EXIF will show which camera shot the image. The main camera has an f/1.7 aperture and a 4.3mm focal length. The secondary zoom camera has an f/2.4 aperture and a 6mm focal length.