One of those "clandestine" portraits I used to capture on my trips .. Used this method for many years - street shooting through out my journeys.
I shot with a Rollei SL66/tripod and a waist-level finder --150mm -- because the focusing knob protruded well-off the body --looked like a lens :-)
You never looked at your subject directly --always off in the exact opposite. You turn the lens towards the subject , of course. BUT you look ahead > far off -- whilst your camera /lens is sideways = pointed left or right of your body position , on the the tripod ....cable release ready and fire -- usually about 1/15 shutter.