like, similar, resemble, pretty, disguise oneself as, dress up, pine away
俏 centers on outward appearance and resemblance: looking like something, dressing up to look pretty, or disguising oneself. The sense of pining away is a less common extension of focusing on one's appearance.
俏 combines 亻 (person) with 肖, which likely contributes the sound and the idea of resemblance or likeness. The exact historical development is uncertain.
A person 亻 beside 肖, a component associated with likeness: imagine someone dressing up to resemble a pretty image, or disguising themselves to look like someone else.
For ショウ, picture a person dressing up for a show: show -> ショウ, and they look pretty and resemble a star.