Size is power

Although this is logical for children vs teenagers vs adults who do have a certain logical relation with this group, this is more for the same type having varying sizes that reflect their power and such.

So, human children being weaker than human adults does NOT count. Regular humans being weaker than some giant humanoids does not count either. However, if you see a person who is 5'7" and another who is 5'11" and the latter is inexplicably more powerful (well, size does give additional strength same way being fat does), then this would count.

Some 3D games take this literally with the characters growing in size with each level or powerup.

Makes absolutely no sense when talking about skill or other non-physical power.