One fascinating similarity between the ghosts in M. R. James's two short stories "Oh, Whistle, and I'll Come to You, My Lad" and "Count Magnus" concerns the fact that neither witness gets to see the actual faces of the ghosts, and whether or not the ghosts actually have faces is debatable.
In "Count Magnus," the narrator relates that while Mr. Wraxall was running from his pursuers, he "came to a cross-road," where he saw two motionless figures in "dark cloaks," one wearing a hat and the other a hood, but he was unable to see the faces of either figure. Similarly, in "Oh, Whistle, and I'll Come to You, My Lad," the boy who saw the figure in the window waving at him said he "couldn't see its face." Also, when Professor Parkins is visited by the apparition in the night and when the apparition rises from the second bed, Parkins is only able to see it as a "band of dark shadow" and unable to see "what its face was like."
In contrast, at the moment Parkins comes face to face in a struggle with the apparition in front of the window, he is able to see that its face was not a human face but the "face of crumpled linen."
Not being able to see the ghosts' faces produces a very supernatural and spooky effect. The description of the ghosts having no faces makes the reader see the ghosts as being other than real people, which makes it easier for the reader to believe in the supernatural.