As the movements are bumpy and not smooth, this shot is certainly filmed with a hand-held camera without the use of a Steadicam.
The use of a hand-held camera is not enough to create a point-of-view shot. It is the hand that picks up the mask and the impression of it being placed on the face of the person whose viewpoint is that of the camera that finally confirm that the shot is subjective. As for the camera’s height, this is may indicate (especially on the stairway) that the point of view is meant to be that of a child.
