Drawing a portrait is not a one sided affair. The model strikes a pose thus inspiring the artist to draw in a very specific way.
In a way by drawing a "portrait" of someone else, an artist leaves a record of their mood, their personality and their take on the model and on the reality. This record can be seen as a "portrait" of the artist.
During the Wandering Cricket Night Market we challenged the participants' expectations by asking them to draw a portrait of us. Time to do it? One minute.
It's quite enough time to get a first impression and to leave a mark without judging proficiency in drawing.