What does "Well-received" mean here?

It's an ambiguous phrase and can mean they are acknowledging receipt or it could mean they were satisfied with the content of the video.

Typical corporate response.

It's a confirmation they received it

Well-received usually means the item in question (a book, a movie, a video) met with approval from its audience.

I don't know how your prospective employer defines it.

It means someone went to church and received the gift of salvation. It means that the whole congregation got rowdy and jumped around and people were screaming and hollering Praise Jesus and filling up water balloons with holy water and throwing them at each other and before long a huge Riot broke out in the police and National Guard showed up and had to use rubber bullets and tear gas bombs and what are we talking about again?

Their meaning is ambiguous. In context, it appears that they're acknowledging that the video was received by them, but that's a strange way to phrase that.

I would expect the term "well received" to be used in a different context, such as someone saying, "Your submission was well received," but that doesn't appear to be what they meant.

Have you asked for clarification?

Well received is just a confirmation of receipt. I always respond to people as such when I receive something that requires an action on my part, and I don't have time to check what they sent on the spot, and give a feedback. So I just say well received. It only means that I saw their email, doesnt mean that I've checked everything and that the matter is closed.

It means that it went down well with the audience

It means the people who saw it liked it.

basically what it means is what ever you said the where impressed by[lookingforthesummer]

I think its just means its been received mate from a northern uk point of view lol

They received it and it was sufficient for what they had asked you for.

It would confuse a native English speaker as well.