One is assuming a position and making an impression (8)
I believe the answer is:
imposing
'one is assuming a position and making an impression' is the definition.
I can't judge whether this defines the answer.
'one is assuming a position and making an impression' is the wordplay.
'one is' becomes 'I'm' ('one is' can formally or humorously mean 'I am').
'assuming' is a charade indicator (letters next to each other).
'a position' becomes 'pos' (abbreviation).
'and' is a charade indicator (letters next to each other).
'making an impression' becomes 'ing' (I can't justify this - if you can you should believe this answer much more).
'im'+'pos'+'ing'='IMPOSING'
Can you help me to learn more?
(Other definitions for imposing that I've seen before include "Majestic" , "Enormous - levying - striking" , "Impressive in appearance" , "Dictating; impressive" , "Taking liberties" .)