Why does Riley have 5’9 energy?

I never knew “height energy” was a thing until people commented on Riley being 6’1 as a surprise. What makes him seem short? Does he not have the machismo of gradient? Is his frame too slight? His voice too high? What is this phenomenon? Why can’t Riley be a convincing 6 foot +. Why does he not even reap the benefits of this gift that god gave him?