These design elements have the shape of the "Isis-knot" amulet and would have decorated the side of a chair.
From Giza, G 7600 S.E. 77. 1929: excavated by the Harvard University-Museum of Fine Arts Expedition; 1929: assigned to the MFA by the government of Egypt. (Accession Date: January 1, 1929)
Harvard University—Boston Museum of Fine Arts Expedition