The carving represents Christ after being whipped, in the so-called "Ecce Homo" representation. This theme comes from the New Testament: John19: 4-6, representing Christ while Pontius Pilate, governor of Judaea, said "Here is the man!" to the Jewish waiting outside the building where trial was taking place.
The angels are holding two symbols of the passion: the column, symbol of the flagellation, and the wood, symbol of the cross Christ would carry and, later, be crucified on. These themes were not widely represented before the 15th century, but later on evolved in the themes of "Christ of the Pietà" and "Christ Man of sorrows", or other themes like the "Crowning with thorns", also representing a scene from the Passion.