Yi In-mun's courtesy name was Munok (文郁) and his sobriquets Kosong Yusugwan Doin (古松流水館道人), Yuch'un (有春), and Chayŏn-ong (紫煙翁); his lineage was of Haeju. Having served in the posts of magistrate of Yŏnp'ung County and Ch'ŏmjŏljesaYi In-mun was born in the same year as Kim Hong-do, and the two men sustained a close friendship throughout their lives, each exerting an influence upon the other. He left behind works across a wide range of genres, but achieved particular distinction through a comprehensive landscape style that synthesized elements of both the Southern and Northern Schools. In this respect he is sometimes compared to Kim Hong-do and Sim Sa-jŏng (沈師正).
This work is a painting of immortals depicting a celestial youth seated against a deer beneath a pine tree. Holding a horsehair whisk (pulja), the youth wears his hair bound up in two topknots and carries a gourd and a book. At the base of the pine, small lingzhi mushrooms grow here and there, signaling that the setting is a remote mountain depth inhabited by immortals. The iconographic identity of the figure is not entirely clear, yet among Chosŏn period paintings of immortals one does encounter the Deer Immortal — a young boy accompanied by a deer — with some frequency. The composition is bold: the ground is divided along one diagonal, while the pine is disposed along the opposing diagonal, creating a dynamic sense of both spatial recession and movement. The deer is rendered with short strokes aligned along the body's contours to evoke the texture of fur, with rounded ink dots substituting for the depiction of the spine — a characteristically Kimhong-do approach — while the pine is drawn with uninhibited, sweeping brushstrokes; yet these elements are thoroughly assimilated into Yi In-mun's own accomplished and personally distinctive handling of brush and ink. Behind the pine, a vaguely suggested rock face is painted in dilute ink, with a waterfall hanging vertically against it left as luminous white unpainted paper.
The treatment of the pine and the handling of the background are closely akin to those in Viewing a Waterfall beneath a Pine (松下観瀑圖) in the Hoam Art Museum. The Gansong Art Museum holds a work entitled Celestial Youth Preparing Medicine (仙童煎藥圖) that shares an identical background and compositional structure with the present painting, differing only in that the celestial youth is there rendered as an ordinary tousle-headed boy boy brewing tea; the motifs — the seated deer, the somewhat stylized pine, the dimly visible cliff face and waterfall, the lingzhi, and the rolled scroll carried by the youth — together with the overall composition and brushwork, are otherwise identical. The work bears a white-text square seal reading Yi In-mun-in (李寅文印).