The Arch depicts the sacking of the Temple at Jerusalem after Titus conquered the city (and is interesting because it probably depicts the treasures of the Temple as they actually appeared – they were almost certainly brought back to Rome and paraded at the Triumph). Jews throughout the centuries have understandably not been very happy about this.
The Jewish tradition of breaking a wine glass at the wedding supposedly derives from
It seems to me that your vase-smasher was following this Talmudic practice of smashing a vase so “people wouldn’t be too happy” in protest of the Sacking of Jerusalem.
http://yourjewishspeech.com/tag/smash-a-glass-at-the-wedding/