As a reptile has few facial features which can be arranged
into expressions which can then be recognized and related-to, I was forced to
improvise: I first positioned the eyebrows into a tall arch. This gave the
lizard a look of sentience and comprehension - a good starting point. By keeping
the nostrils un-flared and the mouth closed, with the edges curved down, I
avoided as much as possible the impression of aggression or malevolence.
Still, at this point it wasn't enough. But by tilting the
head slightly back and to the side, I produced an air of lofty concern, mixed
with - perhaps - a little patience: a look such as a wizened old master might
give his headstrong young pupil. I decided that this would fit well into my
research, as it shows how a necessary feature, instead of being directly
alluded to by a visual cue, might instead be implied by it.