She sits horizontally on a quoin, the dressed cornerstone of the tower, oriented outward rather than upright, which is itself an unusual arrangement. This is a sheela-na-gig, a category of medieval stone carving found across Ireland and Britain depicting a female figure explicitly displaying her genitalia. Their precise meaning remains contested; theories range from fertility symbols to apotropaic figures intended to ward off evil, and their survival on ecclesiastical and defensive structures alike suggests they carried some weight of significance to the people who placed them there.

The figure at Clomantagh has been described in detail by the scholar Barbara Freitag, whose 2004 study of sheela-na-gigs provides one of the most thorough catalogues of such carvings. Her description is precise: the figure is set within a recessed frame, the head resting on a long, thin neck, with flat breasts and wavy lines across the torso that appear to represent ribs. The left arm crosses the body, the hand touching a square cavity that marks the vulva. The right arm bends at the elbow and raises upward toward the head, with a deep groove that may indicate a hand or band. A thicker band appears on the left side of the head before disappearing behind the raised arm, a detail Freitag notes as resembling a sheela at nearby Freshford. The legs are widely splayed, knees bent at right angles, feet turned outward, and an elongated object is placed on the pudenda. The carving is large relative to many examples of its type, and the level of anatomical and compositional detail suggests a confident carver working within an established tradition.

The figure is set almost at roofline height on the tower house's southwest corner, which means it is not easily examined from ground level without knowing precisely where to look. The south face of the castle is the place to focus attention, and an awareness of the fourth-floor line helps orient the eye toward the right section of the quoin. The castle itself is the primary structure on the site, and the sheela is best understood as part of it rather than as a freestanding monument.