Originally Posted by infrequent
Yes the secondary (56mm) lens is only engaged if you choose the Portrait mode but in practice if its engaged, it typically stays in that mode until you change it back. For example if you picked Pano option and shot one, the next time you invoke the camera app it is in Pano mode. Presumably this will hold true until the app state memory is cleared or the phone is switched on/off.
Perhaps a nitpick but: this is not true.
The secondary lens is engaged during two situations: when the camera is set to "zoom 2x", and when the camera is in "portrait mode". The functions of the two situations are different. During "Portrait Mode" both lenses are used and the software pretends to create blurred, out-of-focus areas behind the main subject (which it guesses at). The results really aren't bad, but you have to know what they are (given the size of the sensor and the fixed aperture basically everything is in focus). When any of the camera modes are selected besides "Portrait Mode" and the zoom is set to "2x" then the secondary lens is used alone. Only the primary lens has image stabilization built in, so in 2x mode this isn't available.