In the case of the 2015-vintage Wacom Cintiq Companion 2, this turns out to be the so-called Athena chip, which switches the display input between the HDMI port and internal display controller.

Wacom, purveyors of fine pen tablets for digital ... The second product line, the Cintiq, takes the same technology and adds an LCD to the mix, effectively turning a drawing tablet into a second ...