He's not in a position a motorbike would take actually. A motorbike would be on the right of the centre line of thHe's in the position a motorbike would usually take. Completely unnecessary to be that far from the kerb on the single lane stretch of road on a bicycle.
The guy has no hazard awareness.
You'd do that if something was coming towards you. Bikers wouldn't drive in the centre if it's dry as that's where all the shit/ oil is.It's recommended that motorbikes take a position in centre the or slightly to the right of center.
However on that particular stretch of road it's best to drive slightly left of centre as it's a busy stretch and this will allow space for oncoming traffic to swerve in the event there is a hazard on their left.