Which new zealand cultural tradition is represented in the photo above?

The haka is a traditional war cry, war dance, or challenge in Māori culture. It is a posture dance performed by a group, with vigorous movements and stamping of the feet with rhythmically shouted accompaniment.[a]

War haka were originally performed by warriors before a battle, proclaiming their strength and prowess in order to intimidate the opposition, but haka are also performed to welcome distinguished guests, or to acknowledge great achievements, occasions or funerals, and kapa haka (performing arts) groups are very common in schools.

they were chasing the bread.