What is the meaning of "it's the herald of ~"?
In this context, "herald of" is used to mean a person or thing that is a sign that something is about to happen. The speaker in this video has used it to humorously exaggerate that a snack dawn (new period of snacking) is about to happen. He then turns over a pail of snacks, which is the "snack dawn" he said would happen. Ex: The little flowers were the herald of spring. Ex: The government announcement was the herald of a new policy direction. "Herald" can also be used as a verb. Ex: The flowers heralded the start of spring. Ex: The announcement heralded a change in government policy.