The moral of this custom has two aspects:
1. Infant urine has special significance in traditional culture. Traditionally, urine can drive away evil spirits and bring good luck. Therefore, putting a urine bucket under the bed of the newlyweds means that the couple will give birth to a good child, and at the same time, it can also exorcise evil spirits.
2. The child carrying the urinal symbolizes that the marriage of the newlyweds will be smooth sailing, and it also indicates that the newlyweds are about to give birth to a baby.
In short, it is a traditional marriage custom in rural areas to let children carry urinals, which is a blessing and implication for newlyweds when they get married.