Writing about the illustrations of John Tenniel and their theatricality (e.g.), I remembered there being a single word for the expression of character through a person's posture, movement, and/or countenance, but I can't think of the word.
I've searched for synonyms for 'theatrical' and 'caricature', but nothing came up. I feel as if it is somehow linked to 'hysteria', but idem ditto.
It's not 'histrionic', because that doesn't necessarily suggest a connection between the character of the person and their behaviour.
Neither is it limited to theatricality or the theatre, as these behaviorisms tend to occur naturally. It is however often used in theatre and illustrations, so the audience gets a direct and clear idea of the actors.
A recognizable example of the concept would be how a sly character stoops and squints. Another would be how J. J. Grandville chose the animals for his anthropomorphic characters.
NB If there is anything I can add to improve my question, please let me know!