Li Shi had a keen eye and had studied photography and painting, especially the latter. He had learnt art anatomy and classical human figure drawing, and had given deep thought to the relationship between superficial appearances and bone structures.
Therefore, he was originally very confident.
Most twins, even identical ones, would always present some differences in height, skin birthmarks, moles, and such, and would undergo bodily changes due to habits and personality differences developed over time.
For example, speech mannerisms, catchphrases, speaking rates, etc., would result in corresponding changes to a person's oral musculature and skeletal structure.
But when he delved deeper into this game, he was surprised to find out that, despite understanding all the theoretical knowledge, he had some difficulty distinguish who is the older sister and who is the younger one when it came to practical application.