The larger the sensor the more light the sensor captures yielding in better image quality.
23.6 x 15.6mm
Polaroid Snap: 81.2 x 25.4mm
3. focus points
The more focus points the more flexibility in picking which part of the scene to focus on. They also give the image sensor a better probability in identifying the right area of the scene to focus on in more automatic modes.
Sony Alpha a9: 693
4. continuous shooting at high resolution
Fast continuous shooting is useful for catching action shots.
Olympus OM-D E-M1 Mark II: 60fps
The maximum ISO at which the device still captures excellent quality images. Source: DxOMark.
Sony Alpha 7S: 3702ISO
6. has a flip-out screen
Flip-out screens are useful for doing tricky shots.