Carnival has a brand ambassador. So does One Crew One Voice. The title is where the similarity ends.
Carnival's brand ambassador is a company role, held by a company man on a company salary. The job is the brand: promote the ships, sell the fun, host the page, fill the feed with sailaways and smiles. When a hard question about crew comes up, the answer is the company's answer, because it has to be. He will never tell you how the gratuities are pooled, what a steward's day actually runs, or why the crew mess serves what it serves. He cannot. That is not a criticism of the man. It is the job description.
Ours is not a job and it does not come with a salary, a script, or permission. A One Crew One Voice brand ambassador is a crew member or a passenger who carries the stickers, tips in cash so the money reaches the person who earned it, tells one crew member about the rest tracker and their rights, and shares the films the lines would rather you never saw. Nobody approves the posts. Nobody can be fired from it by a marketing department. The credential is the opposite of a payroll: the lines ban ours, and the bans are the receipt.
Paid by: the cruise line, versus nobody.
Speaks for: the brand, versus the crew.
The script: approved by marketing, versus whatever the truth is that day.
On gratuities: pre pay them and smile, versus tip cash and ask where the pool goes.
If they criticise the line: they lose the job, versus they get banned and keep going.
Want the title? It is earned, not appointed. Order the stickers, put them on your tip money, and tell one crew member the truth. That is the whole induction ceremony.