There are several places in realMyst where an object takes the shape of the Cyan logo:
I've collected images of all the places I've found.
Myst Island: New control panel behind old imager control panel
Mechanical Age: Symbol in control panel
Mechanical Age: Control mechanism for elevator rotation
Mechanical Age: Shadow on top of elevator (suggested by A'Reandal)
Mechanical Age: Fortress Rotation Simulator (suggested by A'Reandal)
Selenitic Age: Pool
Selenitic Age: Gear (?) by clock tower
Selenitic Age: Map
