During the visuals for "Sandcastles," a frank and heartfelt ballad that features a cameo by her husband, Jay Z, Beyoncé plays the piano while sitting on the floor in a home with minimalist decor. The camera pans to one object, a bowl sitting on the counter. The piece is Kintsukuroi, the Japanese art of repaired pottery. Broken objects are pieced back together with lacquer, typically in gold, silver, or platinum. The philosophy behind the technique is to celebrate the flawed or imperfect, rather than disguise it, and that the piece becomes more beautiful for having been broken.
Given the sentimental undertone of the song's lyrics — Beyoncé sings "We built sandcastles that washed away" and "Show me your scars and I won't walk away" — and as they are purported to be about a rough patch in her own marriage, it makes sense why Beyoncé would include the symbolic piece in the video as a possible metaphor for her relationship.
