the user of the *upward* nod of acknowledgement displays the nostrils and their contents to the subject, whilst symultaneously looking down on them
(supplementary) the *upward* nod of acknowledgement has quite different connotations to the *downward* nod of acknowledgement
"the user of the *upward* nod of acknowledgement displays the nostrils and their contents to the subject, whilst symultaneously looking down on them" What is the definition of "nod of acknowledgement"?