The bowstands of the Luba have been described in the early literature by European visitors to southeastern Zaire. Father Colle
reported that bowstands could be made of either iron or wood. They were placed next to the conjugal bed, driven into the
ground or into the wall of the house (Colle 1913:167-8). The arrows placed on the stand were symbols of the union of marriage
-- during the wedding ceremony an arrow is placed in the ground before the parents of the bride and groom to symbolize the
indissoluble nature of the marriage (Sendwe 1955:61, Preeraer and Manoly 1938:11).

Others reported that the bowstand was a symbol of chiefly power (de Maret 1973:10, Hall 1923:192-197). The bowstand is
placed before the chief to hold his bow and arrows. A woman of high rank is the only person who is allowed to care for the
object (Cornet 1972:212, Tatum 1984).

Another interpetation:
Luba bowstands are rare and highly sought after by collectors. They were placed behind a Luba king's thrown and used to hold
his bow. Bow stands are amongst the most critical items in the Luba King's treasury, and were never displayed in public.
Instead, they were guarded in the King's residence by a female dignitary named Kyabuta. During public ceremonies, the
Kyabuta followed the chief with a simple bow held between her breasts. Bow stands were provided with prayers and sacrifice,
were subject to elaborate ritual and taboo and commemorate actual woman in Luba history.

Sources: A History of Art in Africa / Africa - The Art of a Continent / The Tribal Art of Africa / The Dance, Art and Ritual of Africa
I currently do not have a bowstand in my collection - the examples below are for reference purposes
Examples of traditional Luba bowstands
older Luba bowstand
Antwerp museum
Bow Stand with Female Figure, 19th–20th century
Democratic Republic of Congo; Luba
Wood, metal, beads, string; H. 38 1/2 in. (97.8 cm)
The Michael C. Rockefeller Memorial Collection, Purchase, Nelson A. Rockefeller Gift
and The Wunderman Foundation Gift, 1963 (1978.412.486)
The Metropolitan Museum of Art
to go to the African scarification page to see examples of scarification similar to the ones you see on Luba sculpture