Could be a way of loosing speed and/or altitude on finals when too fast or too high...though not really recommended in an airliner at night with passengers with no visible terrain features.
You turn left or right, all the way to 360 degrees, gives you time/distance to re-adjust stabilised parameters for a stable approach and landing.
I would keep this kind of maneuver to last resort and day VMC only.
The standard approach would be to perform a go-around.
Flex