[na-adj] + な + 姿
[verb (ている form)] + 姿
The expression ~(の)姿 describes someone's visual appearance, figure, or form – how they look in a particular outfit, state, or while performing an action. すがた姿 (すがた) literally means "figure" or "form," and this pattern is used to capture the image or sight of a person (or sometimes an animal/thing) as perceived by an observer.
When attached to a noun (typically clothing or a condition), の姿 describes how someone looks dressed in or in the state of that noun.
This is used with clothing items like せいふく制服、すうつスーツ、きもの着物 and states like げんき元気なすがた姿 (a healthy/energetic appearance).
When attached to a verb in plain form, 姿 captures the image or sight of someone in the act of doing something. No の is used between the verb and 姿.
This usage often conveys an emotional reaction – admiration, nostalgia, sadness – at witnessing someone's figure or form. It is frequently paired with verbs of perception like みる見る、みかける見かける、ながめる眺める.
The ている form can also precede 姿 to describe the appearance of someone in an ongoing state or resulting condition.
~(の)姿 tends to carry a visual and often emotional tone. It is used in descriptions that evoke feelings – seeing a loved one's figure, watching someone's efforts, or noticing a change in someone's appearance.