What is the Buddhist perspective on body language? Some explain that body language affects qualities like leadership, command, personality etc.: 

Your body language shapes who you are

What is the Buddhist perspective on body language? Does body language affect mental qualities?
There are many examples in Buddha's life how others were inspired by his appearance.
King Bimbisara was tempted to offer him a palace seeing his stature on the first encounter (this was before his enlightenment),


  Look at this one, sirs. How handsome, stately, pure! How consummate
  his demeanor! Mindful, his eyes downcast, looking only a plow-length
  before him, as one who's not from a lowly lineage: Send the royal
  messengers at once to see where this monk will go.
  
  [..]
  
  "You are young, youthful, in the first stage of youth, endowed with
  the stature &amp; coloring    of a noble-warrior. You would look glorious
    in the vanguard of an army,     arrayed with an elephant squadron. I
  offer you wealth : enjoy it. I ask your birth : inform me."
  
  Sn 3.1


Maha Kassapa accepted him as his teacher without hearing a word from him,


  On the road between Rajagaha and Nalanda, the Master sat down under a
  fig tree, waiting for his future disciple. When Kassapa arrived at the
  spot and saw the radiance of the Buddha's countenance, sensing the
  enlightenment that shone through it, he thought, "This must be my
  Master for whose sake I have gone forth!" He approached the Buddha,
  and paying homage, fell at his feet and exclaimed: "The Exalted One,
  Lord, is my teacher, and I am his disciple!"
  
  http://www.accesstoinsight.org/lib/authors/hecker/wheel345.html#ch4


The occasion where Milinda was introduced to Nâgasena in Milinda panha gives some insight on how Buddhist literature sees the influence of body language.
Nâgasena was a junior monk, yet Milinda was able to recognize him among others by his demeanor,


  And as he looked over the whole of the assembly, in front, and down the centre,
  and behind, king Milinda detected Nâgasena seated in the middle, and,
  like a shaggy lion who knows no fear or frenzy, entirely devoid of
  nervous agitation, and free from shyness and trepidation. And as soon
  as he saw him, he knew by his mien that that was Nâgasena, and he
  pointed him out to Devamantiya.


Now, this is a king that gets nervous and frightened by the sight of a monk.


  Whereupon the king rejoiced that he had recognised Nâgasena without having had him pointed out to him. But nevertheless, at the sight of him, the king was seized with nervous excitement and trepidation and fear.


This encounter conditions the king's mind, the king has accepted defeat by the very sight of this monk.


  'At the sight of Nâgasena, wise and pure, Subdued in all that is the
  best subjection, Milinda uttered this foreboding word-- "Many the
  talkers I have visited, Many the conversations I have had, But never
  yet, till now, to-day, has fear, So strange, so terrible, o'erpowered
  my heart. Verily now defeat must be my lot, And victory his, so
  troubled is my mind".