Have a close look at the first two photographs. Those are four strip light portraits composed into one family portrait 

 

 

 

Although this is quite some popular editing style, here is a common mistake. All individual photographs are taken with the same distance to the models. When composing the models appear to stand next to each other but partly behind each other so that the distance to the camera appears different in the composing. By doing so the propotional size of he models does not seem to match reality.

This effect is not related to displaying he smallest head to the left or in front of the others respectively. To demonstrat that I composed the faces from the smallest to the largest and vice versa.

Why is that?