In the 1990’s Thomas the Tank engine short films showed him with fixed facial expressions.
The same facial expressions have been included with O gauge and G gauge versions of Thomas the Tank Engine.
Thomas the Tank Engine could have an operating face.
Robotics and plastics have been refined to the point that very realistic faces are being built by David Hanson. They can mimic human expressions and voices with the robotics moving under the skin being controlled by interactive computer systems.
http://earthsky.org/biomimicry/david-hanson-creates-robots-with-human-faces
The first Thomas the Tank Engine these expressive faces and interactive voices could be applied to is the full size version at the Strasburg Railroad. Now that Thomas has a solid molded face, but it would be more amazing if the David Hanson team designed the software and hardware to create an interactive version of Thomas.
Then the technicians at toy train and model railroad companies like Lionel and Bachmann can make miniaturized versions of this technology.
Andrew Falconer