An unsual ghost view in which the photographer has done a double-exposure to add Marley's ghost to the scene. This photographic effect was not so obvious at the time as it seems now. It was proposed by David Brewster, who invented the first practical stereoviewer and was instrumental in popularizing the medium:

For the purpose of amusement, the photographer might carry us even into the regions of the supernatural. His art, as I have elsewhere shewn, enables him to give a spiritual appearance to one or more of his figures, and to exhibit them as 'thin air' amid the solid realities of the stereoscopic picture. While a party is engaged with their whist or their gossip, a female figure appears in the midst of them with all the attributes of the supernatural. Her form is transparent, every object or person beyond her being seen in shadowy but distinct outline. …In order to produce such a scene, the parties which are to compose the group must have their portraits nearly finished in the binocular camera, in the attitude which they may be supposed to take, and with the expression which they may be supposed to assume, if the vision were real. When the party have nearly sat the proper length of time, the female figure, suitably attired, walks quickly into the place assigned her, and after standing a few seconds in the proper attitude, retires quickly.. If this operation has been well performed, all the objects immediately behind the female figure, having been, previous to her introduction, impressed upon the negative surface, will be seen through her, and she will have the appearance of an aerial personage, unlike the other figures in the picture. (The Stereoscope, Its History, Theory, and Construction, Chapter XIV, 1856.)