I would really appreciate some help here because I am absolutely clueless regarding the meaining of the phrase in bold (a ghost story by A. Blackwood http://algernonblackwood.org/Z-files/Deferred_Appointment.pdf):
At length everything was ready, only the flashlight waiting to be turned on, when, stooping, he covered his head with the velvet cloth and peered through the lens— at no one! When he says “at no one,” however, he qualifies it thus: “There was a quick flash of brilliant white light and a face in the middle of it—my gracious Heaven! But such a face— ’im, yet not ’im—like a sudden rushing glory of a face!