The dragon and phoenix pairing is the oldest surviving wedding motif in Chinese decorative art: the dragon representing the groom and the phoenix the bride, appearing as a matched pair on robes, lacquer and ceramics from the imperial period onward.
The two plaques here are nephrite jade, carved from the same block so their colour and veining correspond, and mounted either side of a silk-lined box. Nephrite is one of only two minerals properly called jade; it is worked by grinding and is identified clearly here rather than sold under a vague description.