The Advent wreath is a tradition that observes the passage of time leading up to Christmas. Candles are lit around the wreath, laid horizontally on a table, during the weeks leading up to Christmas Day. Take that same horizontal wreath and suspend it in the air and you have a play on the wreaths we more typically see hanging upright.
Several of the sources shown here are Swedish, and Martha herself calls it a Swedish-style wreath. We're not sure of the Swedish roots of the Advent wreath, but we sure like the idea of hanging one chandelier-style over the table or entryway!