Customization is the primary driver of realism in synthetic companions, transforming a generic figure into something uniquely convincing. Realism emerges from a combination of anatomical accuracy, expressive features, and tactile fidelity. Mechanical joints and articulated structures should allow natural ranges of motion that mirror human posture, while internal supports must maintain stability in sustained poses. Skin textures, color variations, and micro-details such as blush, freckles, or subtle asymmetry contribute to the illusion of life and individuality.

Facial realism often hinges on nuanced sculpting and painting. Fine lines, pores, and subtle asymmetries can make a portrait feel more authentic, while the ability to adjust expressions—slight smiles, neutral gazes, or intent looks—adds emotional depth. Beyond physical attributes, customization can extend to hair, eye color, and even scars or marks that tell a personal backstory. Beyond appearance, user-driven options like fragrance, warmth, or scent profiles—though more conceptual—can enhance perceived realism in a domestic setting. The more tailored the choices, the closer the final product will align with a user’s vision. Customization, therefore, is not just about appearance but about shaping a believable presence that resonates on a personal level.