A circuit board.

"In medicine, technological advancements are judged by their ability to improve access to care, decrease its cost or improve its quality," said Bressman regarding the new hologram doctors. “I don’t know of any data to support the idea that this would improve the quality of the visit beyond a usual telemedicine visit,” 

Citation:

"Your Hologram Doctor Will See You Now," The New York Times, H Sanders, June 29, 2024.